day 23

2220.转换数字的最少位翻转次数

int minBitFlips(int start, int goal){int a[100]={0},b[100]={0};int t1=0,t2=0,t,x=0;while(start!=0){a[t1++]=start%2;start/=2;}while(goal!=0){b[t2++]=goal%2;goal/=2;}if(t1>t2){t=t1;}else{t=t2;}for(int i=0;i<t;i++){if(a[i]!=b[i]){x++;}}return x;
}

2236.判断根节点是否等于子节点之和

bool checkTree(struct TreeNode* root){if(root->val==root->left->val+root->right->val){return true;}return false;
}

2278.字母在字符串中的百分比

int percentageLetter(char* s, char letter) {int x1=strlen(s),x2=0;for(int i=0;i<x1;i++){if(s[i]==letter){x2++;}}return (x2*1.0/x1)*100;
}