牛客网华为机试java版

HJ1 字符串最后一个单词的长度
HJ2 计算某字符出现次数
HJ3 明明的随机数
HJ4 字符串分隔
HJ5 进制转换
HJ6 质数因子
HJ7 取近似值
HJ8 合并表记录
HJ9 提取不重复的整数
HJ26 字符串排序
HJ80 整型数组合并
HJ101 输入整型数组和排序标识，对其元素按照升序或降序进行排序

HJ1 字符串最后一个单词的长度

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方法1：用时20ms

import java.util.Scanner;
public class Main {public static void main(String[] args) {Scanner in = new Scanner(System.in);String s = in.nextLine();if(s.length() > 5000)return;Integer index = s.lastIndexOf(" ");String word = s.substring(index+1);System.out.print(word.length());}
}

方法2：用时8ms

import java.util.Scanner;
import java.io.*;// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException{InputStream inputStream = System.in ;int length=0;char c;while('\n' != (c=(char)inputStream.read())){length ++ ;if(c == ' '){length = 0;}}System.out.println(length);}
}

HJ2 计算某字符出现次数

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方法1：用时30ms

import java.util.Scanner;// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) {// Scanner in = new Scanner(System.in);// String first = in.nextLine();// char second = in.next().charAt(0);// int times = 0;// for(int i=0;i<first.length();i++){//     char te = first.charAt(i);//     if(second == te || second == te - 32 || second == te+32){//         times++;//     }// }// System.out.print(times);Scanner in = new Scanner(System.in);String s = in.nextLine().toLowerCase();String b = in.nextLine().toLowerCase();System.out.println(s.length() - s.replaceAll(b, "").length());}
}

方法2：用时6ms

import java.io.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException {int count = 0;BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));char[] first = bufferedReader.readLine().toLowerCase().toCharArray();char[] second = bufferedReader.readLine().toLowerCase().toCharArray();char tar = second[0];for(char c : first){if(c == tar){count++;}}System.out.print(count);}
}

HJ3 明明的随机数

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方法1：用时10ms

import java.io.*;
import java.util.Arrays;
import java.util.HashMap;
public class Main {public static void main(String[] args) throws IOException {BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));Integer n = Integer.parseInt(bufferReader.readLine());HashMap<String, String> hashMap = new HashMap<String, String>();for (int i = 0; i < n; i++) {String str = bufferReader.readLine();if (str != null) {if (!hashMap.containsKey(str)) {hashMap.put(str, "");}}}Object[] keyArray = hashMap.keySet().toArray();Integer[] list = new Integer[keyArray.length];for (int i = 0; i < keyArray.length; i++) {list[i] = Integer.parseInt(keyArray[i].toString());}Arrays.sort(list);for (int i : list) {System.out.println(i);}}
}

方法2：用时8ms

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public class Main {public static void main(String[] args) throws IOException {BufferedReader bf=new BufferedReader(new InputStreamReader(System.in));String str;while((str=bf.readLine())!=null){boolean[] stu=new boolean[1001];StringBuilder sb=new StringBuilder();int n=Integer.parseInt(str);for(int i=0;i<n;i++)stu[Integer.parseInt(bf.readLine())]=true;for(int i=0;i<1001;i++)if(stu[i])sb.append(i).append("\n");sb.deleteCharAt(sb.length()-1);System.out.println(sb.toString());}}
}

HJ4 字符串分隔

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方法1：用时9ms

import java.io.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException {BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));String str = bufferReader.readLine();int length = str.length();if((length % 8)<8 && (length % 8)!=0){int n = 8-(length % 8);for(int i=0;i<n;i++){str+="0";}}char[] arr = str.toCharArray();String temp = "";for(int i=0;i<arr.length;i++){temp+=arr[i];if((i+1)%8 == 0){System.out.println(temp);temp = "";}}}
}

方法2：用时6ms

import java.io.*;public class Main{public static void main(String[] args) throws IOException{BufferedReader br = new BufferedReader(new InputStreamReader(System.in));String str;while((str = br.readLine())!=null){int len = str.length();int start = 0;while (len >= 8){System.out.println(str.substring(start, start + 8));start += 8;len -= 8;}if (len > 0) {char[] tmp = new char[8];for(int i = 0;i<8;i++){tmp[i]='0';}for(int i = 0; start < str.length(); i++) {tmp[i] = str.charAt(start++);}System.out.println(String.valueOf(tmp));}}}
}

HJ5 进制转换

方法1：用时9ms

import java.io.*;// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException {BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));String str = bufferReader.readLine();if(str.startsWith("0x")){Long n = Long.parseLong(str.substring(2),16);System.out.println(n);}else{Long n = Long.parseLong(str,16);System.out.println(n);}}
}

方法2：用时5ms

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public class Main {public static void main(String[] args) throws IOException {// 先读取控制台输入BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));String str;char[] num_arr =new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};while (null != (str = reader.readLine())) {// 取出 0x 后面的字符串String hexNum = str.substring(2);// 字符串长度，可以用来表示位数int digit = hexNum.length();// 存放十进制结果int result = 0;for (int i = 0; i < digit; i++) {char cur_char = hexNum.charAt(i);int cur_num = indexOf(num_arr, cur_char);result += cur_num * Math.pow(16, digit - i - 1);}System.out.println(result);}}public static int indexOf(char[] arr, char num) {for (int i = 0; i < arr.length; i++) {if (arr[i] == num) {return i;}}return 0;}}

HJ6 质数因子

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方法1：用时10ms

import java.io.*;import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException{BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));String str = bufferReader.readLine();Integer num = Integer.parseInt(str);printPrimeFactors(num);}public static void printPrimeFactors(int number) {while(number % 2 == 0){System.out.print(2+" ");number /= 2;}for(int i=3;i<=Math.sqrt(number);i+=2){while(number % i == 0){System.out.print(i+" ");number /= i;}}if(number>2){System.out.print(number);}}
}

方法2：用时6ms

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public class Main {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new InputStreamReader(System.in));String str;while ((str = br.readLine()) != null) {int num = Integer.parseInt(str);StringBuilder sb = new StringBuilder();for (int i = 2; i <= Math.sqrt(num); i++) {if (num % i == 0) {sb.append(i).append(" ");num = num / i;i--;}}sb.append(num).append(" ");System.out.println(sb.toString());}}
}

HJ7 取近似值

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方法1：用时8ms

import java.io.*;// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException {BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));String str = bufferReader.readLine();        double num = Double.parseDouble(str);int res = (int)num;if(num-res >= 0.5){System.out.println(res+1);}else{System.out.println(res);}}
}

方法2：用时9ms

import java.util.*;
import java.io.*;
public class Main {public static void main(String args[])throws Exception{BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));String str = bf.readLine();int index = str.indexOf(".");int a = Integer.parseInt(str.substring(0, index));int b = Integer.parseInt(str.substring(index + 1, index + 2));if(b >= 5){a++;System.out.println(a);}else{System.out.println(a);}}
}

HJ8 合并表记录

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方法1：用时11ms

import java.io.*;
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException{BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));String str = bufferReader.readLine();int num = Integer.parseInt(str);HashMap<Integer,Integer> map = new HashMap<Integer,Integer>();while((str = bufferReader.readLine())!= null){String[] arr = str.split(" ");Integer key = Integer.parseInt(arr[0]);Integer value = Integer.parseInt(arr[1]);if(!map.containsKey(key)){map.put(key,value);}else{map.put(key,map.get(key)+value);}}Integer[] keys = map.keySet().toArray(new Integer[0]);Arrays.sort(keys);for(Integer i : keys){System.out.println(i+" "+map.get(i));}}
}

方法2：用时8ms

import java.util.*;
import java.io.*;
public class Main {public static void main(String[] args) throws Exception{StreamTokenizer st = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));st.nextToken();      // 分隔符int n = (int) st.nval;   // 强转int[] arr = new int[n];for (int i = 0; i < n; i++) {st.nextToken();int key = (int) st.nval;st.nextToken();int value = (int) st.nval;arr[key] = arr[key] + value;}StringBuilder sb = new StringBuilder();for (int i = 0; i < arr.length ; i++) {if(arr[i] != 0){sb.append(i).append(" ").append(arr[i]).append("\n");}}System.out.println(sb.toString());}
}

题目貌似没说key是连续的，可以使用TreeMap代替普通的数组实现，无非都想要自带的排序效果。

HJ9 提取不重复的整数

方法1：用时10ms

import java.io.*;import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args)throws IOException {BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));String str = bufferReader.readLine();HashMap<Integer,Boolean> map = new HashMap<Integer,Boolean>();char[] arr = str.toCharArray();for(int i = arr.length-1;i>=0;i--){Integer key = Integer.parseInt(arr[i]+"");if(!map.containsKey(key)){map.put(key,true);System.out.print(key);}}}
}

方法2：用时5ms

import java.io.InputStream;public class Main {public static void main(String[] args) throws Exception {InputStream in = System.in;int available = in.available()-1;char[] chars = new char[available];while (available-- > 0) {chars[available] = (char) in.read();}StringBuilder resul = new StringBuilder();for (int i = 0; i < chars.length; i++) {if (resul.lastIndexOf(String.valueOf(chars[i])) != -1){continue;}resul.append(chars[i]);}System.out.println(resul.toString());}}

HJ26 字符串排序

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方法1：用时7ms

import java.util.*;import java.io.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args)throws IOException {BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));String str = bufferReader.readLine();StringBuilder sb = new StringBuilder();for (int j = 0; j < str.length(); j++) {char ch = str.charAt(j);if ((ch >= 65 && ch <=90) || (ch >= 97 && ch <= 122)) {sb.append('0');} else {sb.append(ch);}}for (int i = 65; i < 97; i++) {int m = 0;for (int j = 0; j < str.length(); j++) {char ch = str.charAt(j);char nch = sb.charAt(m);if (ch == i || ch == i + 32) {if (nch == '0') {sb.setCharAt(m, ch);while(m<str.length()){m++;nch = sb.charAt(m);if(nch == '0'){break;}}} else {int n = m + 1;while (n < str.length()) {nch = sb.charAt(n);if (nch == '0') {sb.setCharAt(n, ch);m++;break;}n++;}}}}}System.out.print(sb.toString());}
}

方法2：用时6ms

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;public class Main{public static void main(String[] args) throws IOException{BufferedReader br = new BufferedReader(new InputStreamReader(System.in));String s;while((s = br.readLine()) != null){char[] ch = s.toCharArray();char[] chars = new char[ch.length];int flag = 65, j=0;while(flag<=90){for(int i=0; i<ch.length; i++){if((ch[i]>=65&&ch[i]<=90) || (ch[i]>=97&&ch[i]<=122)){if(ch[i]==flag || ch[i]== flag+32){chars[j] = ch[i];j++;}}}flag++;}j=0;for(int i=0; i<ch.length; i++){if((ch[i]>=65&&ch[i]<=90) || (ch[i]>=97&&ch[i]<=122)){ch[i] = chars[j];j++;}}System.out.println(String.valueOf(ch));}}
}

HJ80 整型数组合并

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方法1：用时10ms

import java.util.*; import java.io.*;// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args) throws IOException{BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));Integer first = Integer.parseInt(bufferReader.readLine());Integer[] firstArr = new Integer[first];String[] firstStrArr = bufferReader.readLine().split(" ");HashMap<Integer,Integer> map = new HashMap<Integer,Integer>();for(int i=0;i<first;i++){firstArr[i] = Integer.parseInt(firstStrArr[i]);if(!map.containsKey(firstArr[i])){map.put(firstArr[i],0);}}Integer second = Integer.parseInt(bufferReader.readLine());Integer[] secondArr = new Integer[second];String[] secondStrArr = bufferReader.readLine().split(" ");for(int i=0;i<second;i++){secondArr[i] = Integer.parseInt(secondStrArr[i]);if(!map.containsKey(secondArr[i])){map.put(secondArr[i],0);}}Integer[] res = map.keySet().toArray(new Integer[0]);Arrays.sort(res);for(Integer i:res){System.out.print(i);}}
}

方法2：用时9ms

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;public class Main {public static void main(String[] args) throws Exception {BufferedReader br = new BufferedReader(new InputStreamReader(System.in));String line;while ((line = br.readLine()) != null && line.length() > 0) {String[] strs = br.readLine().split(" ");int[] array1 = new int[strs.length];for (int i = 0; i < array1.length; ++i)array1[i] = Integer.parseInt(strs[i]);line = br.readLine();strs = br.readLine().split(" ");int[] array2 = new int[strs.length];for (int i = 0; i < array2.length; ++i)array2[i] = Integer.parseInt(strs[i]);System.out.println(combineBySort(array1, array2));}}static String combineBySort(int[] array1, int[] array2) {int[] outPut = new int[array1.length + array2.length];Arrays.sort(array1);Arrays.sort(array2);int M = array1.length, R = array2.length;int idx = 0, i = 0, j = 0;if (array1[i] > array2[j]) {outPut[idx++] = array2[j++];} else if (array1[i] < array2[j]) {outPut[idx++] = array1[i++];} else {outPut[idx++] = array1[i++];j++;}while (i < M && j < R) {if (array1[i] > array2[j]) {if (outPut[idx - 1] != array2[j])outPut[idx++] = array2[j];++j;} else if (array1[i] < array2[j]) {if (outPut[idx - 1] != array1[i])outPut[idx++] = array1[i];++i;} else {if (outPut[idx - 1] != array1[i])outPut[idx++] = array1[i];++i;++j;}}if (i == M) {while( j < R){if (outPut[idx - 1] != array2[j])//去重outPut[idx++] = array2[j];j++;}} else {for (; i < M; ++i)if (outPut[idx - 1] != array1[i])outPut[idx++] = array1[i];}StringBuilder sb = new StringBuilder();for (i = 0; i < idx; ++i)sb.append(outPut[i]);return sb.toString();}}

HJ101 输入整型数组和排序标识，对其元素按照升序或降序进行排序

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方法1：用时11ms

import java.util.*;import java.io.*;// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {public static void main(String[] args)throws IOException {BufferedReader bufferReader = new BufferedReader(new InputStreamReader(System.in));Integer sum = Integer.parseInt(bufferReader.readLine());Integer[] arrInt = new Integer[sum];String[] arrStr = bufferReader.readLine().split(" ");for(int i=0;i<arrInt.length;i++){arrInt[i] = Integer.parseInt(arrStr[i]);}Integer sort = Integer.parseInt(bufferReader.readLine());Arrays.sort(arrInt);if(sort == 0){for(int i =0;i<arrInt.length;i++){System.out.print(arrInt[i]+" ");}}else{for(int i =arrInt.length-1;i>=0;i--){System.out.print(arrInt[i]+" ");}}}
}

方法2：用时13ms

/*** @FileName: Test* @Author: KipFcrs* @Date: 2020/8/3 16:27*/import java.util.*;
import java.io.*;public class Main {public static void main(String[] args) throws IOException {BufferedReader br = new BufferedReader(new InputStreamReader(System.in));String inputCount;while ((inputCount = br.readLine()) != null) {int count = Integer.parseInt(inputCount);String[] input = br.readLine().split(" ");int flag = Integer.parseInt(br.readLine());int[] num = new int[input.length];for (int i = 0; i < input.length; i++) {num[i] = Integer.parseInt(input[i]);}quickSort(num,0,num.length - 1);StringBuilder sb = new StringBuilder();if(flag == 0){for (int j = 0; j < num.length; j++) {sb.append(num[j]).append(" ");}}else{for (int k = num.length - 1; k >= 0; k--) {sb.append(num[k]).append(" ");}}System.out.println(sb.substring(0,sb.length()-1));}}public static void quickSort(int[] num, int L, int R) {if (L >= R) {return;}int p = partition(num, L, R);quickSort(num, L, p - 1);quickSort(num, p+1, R);}public static int partition(int[] num, int L, int R) {int key = num[L];int pivot = L;for (int i = L + 1; i <= R; i++) {if (num[i] < key) {int temp = num[++pivot];num[pivot] = num[i];num[i] = temp;}}int tt = num[pivot];num[pivot] = num [L];num[L] = tt;return pivot;}}