第十一届蓝桥杯省赛真题（C/C++大学B组）

试题A ：门牌制作

试题B ：既约分数

试题C ：蛇形填数

试题D ：跑步训练

试题E ：七段码

试题F ：成绩统计

试题G ：回文日期

试题H ：字串分值

试题I ：平面切分（不会）

试题J : 字串排序（不会）

试题A ：门牌制作

#include <bits/stdc++.h>
using namespace std;const int N = 100000;
int arr[N];int main()
{int ans = 0,t;for(int i = 1;i <= 2020;i++){t = i;while(t > 0){if(t % 10 == 2) ans++;t /= 10;}}cout<<ans<<endl;return 0;
}

试题B ：既约分数

#include <bits/stdc++.h>
using namespace std;int gcd(int a,int b)
{if(a % b == 0) return b;return gcd(b,a % b);
}int main()
{int ans = 0;for(int i = 1;i <= 2020;i++){for(int j = 1;j <= 2020;j++){if(gcd(i,j) == 1) ans++;}}cout<<ans<<endl;return 0;
}

试题C ：蛇形填数

#include <bits/stdc++.h>
using namespace std;int arr[100][100];int main()
{int sum = 1; for(int i = 0;i < 50;i++){//奇数，行-，列+ if(i % 2 == 1){for(int x=i,y=1;x >= 0 && y <= i;x--,y++)arr[x][y] = sum++;}//偶数，行+，列-else{for(int x=1,y=i;x <= i && y >= 0;x++,y--)arr[x][y] = sum++;} }cout<<arr[20][20]<<endl;return 0;
}

试题D ：跑步训练

#include <bits/stdc++.h>
using namespace std;bool judge(int year)
{if(year % 400 == 0 || year % 4 == 0 && year % 100 != 0)return true;return false;
}int main()
{int month[12] = {31,28,31,30,31,30,31,31,30,31,30,31};int sum = 0;int w = 6;for(int y = 2000;y <= 2020;y++){if(judge(y)) month[1] = 29;for(int m=1;m <= 12;m++){for(int d = 1;d <= month[m-1];d++){if(d == 1 || w == 1) sum += 2;else sum++;w = w % 7 + 1; if(y == 2020 && m == 10 && d == 1) cout<<sum<<endl;}}month[1] = 28;}return 0;
}

试题E ：七段码

#include <bits/stdc++.h>
using namespace std;//是否连通 
bool con[8][8];
bool vis[8];
int father[8];
int sum;int f(int n)
{if(father[n] == n) return n;else{father[n] = f(father[n]);return father[n];}
}void dfs(int n)
{if(n > 7){for(int i = 1;i <= 7;i++)father[i] = i;for(int i = 1;i <= 7;i++){for(int j = 1;j <= 7;j++){if(vis[i] && vis[j] && con[i][j]){int x = f(i);int y = f(j);if(x != y)father[x] = y;}}}int k = 0;for(int i = 1;i <= 7;i++){if(vis[i] && father[i] == i) k++;}if(k == 1) sum++;return;}vis[n] = 1;dfs(n+1);vis[n] = 0;dfs(n+1);
}int main()
{con[1][2]=con[1][6]=1;con[2][1]=con[2][7]=con[2][3]=1;con[3][7]=con[3][4]=con[3][2]=1;con[4][5]=con[4][3]=1;con[5][4]=con[5][7]=con[5][6]=1;con[6][1]=con[6][7]=con[6][5]=1;con[7][6]=con[7][5]=con[7][2]=con[7][3]=1;dfs(1);cout<<sum<<endl;return 0;
}

试题F ：成绩统计

【样例输入】

【样例输出】

71%
43%

#include <bits/stdc++.h>
using namespace std;int n,n1,n2;
float a,b;int main()
{cin>>n;int score;for(int i = 1;i <= n;i++){cin>>score;if(score >= 60) n1++;if(score >= 85) n2++;}a = 1.0f * n1 / n * 100;b = 1.0f * n2 / n * 100;printf("%.0f%%\n",a);printf("%.0f%%\n",b);return 0;
}

试题G ：回文日期

#include <bits/stdc++.h>
using namespace std;bool judge(int n)
{int t = n;int reverse = 0;while(t > reverse){reverse = reverse * 10 + t % 10;t /= 10;}//cout<<reverse<<"--"<<t;return t == reverse || reverse / 10 == t;
}
bool judgeYear(int n)
{if(n % 400 == 0 || n % 4 == 0 && n % 100 != 0)return true;return false;
}
bool judge2(int x)
{int s[8];int m=1000000;int n=10;s[0]=x/10000000;for(int i=1;i<8;i++,m/=10){s[i]=x/m%n;}if(s[0]==s[2]&&s[2]==s[5]&&s[5]==s[7]&&s[1]==s[3]&&s[3]==s[4]&&s[4]==s[6]){return true;}else return false;
}int main(){int n,str,flag1 = 0,flag2 = 0;cin>>n;int month[13] = {0,31,28,31,30,31,30,31,31,30,31,30,31};for(int y = n / 10000;true;y++){str = y * 10000;int m;if(y == n / 10000) m = n / 100 % 100;else m = 1;for(;m <= 12;m++){str += m * 100;int d;if(y == n / 10000 && m == n / 100 % 100) d = n % 100 + 1;else d = 1;for(;d <= month[m];d++){str += d;if(flag1 == 0 && judge(str)){cout<<str<<endl;flag1 = 1;}if(flag2 == 0 && judge2(str)){cout<<str<<endl;flag2 = 1;}str -= d;}if(flag1 && flag2) break;str -= m * 100;}if(flag1 && flag2) break;}return 0; 
}

试题H ：字串分值

【样例输入】

ababc

【样例输出】

【样例说明】

子串    f值
a        1
ab       2
aba      2
abab     2
ababc    3b       1ba		 2bab	 2babc 	 3a	 1ab	 2abc	 3b	 1bc	 2c	 1

#include <bits/stdc++.h>
using namespace std;int ans;
set<char> s; int main()
{string str;cin>>str;for(int i = 0;i < str.length();i++){s.clear();for(int j = i;j < str.length();j++){s.insert(str[j]);ans += s.size();}}cout<<ans<<endl;return 0;
}