题目：

题解：

typedef struct {int tweetId;int userId;
} Tweet;typedef struct {int* dict[501];Tweet* tweetList;int tweetListLen;
} Twitter;Twitter* twitterCreate() {Twitter* obj = malloc(sizeof(Twitter));for (int i = 0; i < 501; i++) {obj->dict[i] = calloc(501, sizeof(int));obj->dict[i][i] = 1;}obj->tweetList = malloc(30000 * sizeof(Tweet));obj->tweetListLen = 0;return obj;
}void twitterPostTweet(Twitter* obj, int userId, int tweetId) {obj->tweetList[obj->tweetListLen].tweetId = tweetId;obj->tweetList[obj->tweetListLen].userId = userId;obj->tweetListLen++;return;
}int* twitterGetNewsFeed(Twitter* obj, int userId, int* retSize) {int* res = malloc(10 * sizeof(int));*retSize = 0;for (int i = obj->tweetListLen - 1; i >= 0; i--) {if (obj->dict[userId][obj->tweetList[i].userId] == 1) {res[*retSize] = obj->tweetList[i].tweetId;(*retSize)++;}if (*retSize == 10) {break;}}return res;
}void twitterFollow(Twitter* obj, int followerId, int followeeId) {obj->dict[followerId][followeeId] = 1;return;
}void twitterUnfollow(Twitter* obj, int followerId, int followeeId) {obj->dict[followerId][followeeId] = 0;return;
}void twitterFree(Twitter* obj) {for (int i = 0; i < 501; i++) {free(obj->dict[i]);}free(obj->tweetList);free(obj);return;
}