报错多次终于通过的折半查找，记录一下
#include <stdio.h> #include <stdlib.h> int BinSearch(int arr[],int len,int key); int main() { int n; int k; int num[1000001]; int mem[1000001]; int i,j; // 反复读入数字和查找数字的数量 while (scanf("%d%d", &n, &k) != EOF) { //mem = (int*)malloc(k); //num = (int*)malloc(n); // 读入给定的数字 for (i = 0; i < n; i++) { scanf("%d", &num[i]); } for (j = 0; j < k; j++) { // 读入待查找的数字， scanf("%d", &mem[j]); } } for(j = 0 ; j < k ; j ++){ printf("%d",BinSearch(num,n,mem[j])); if(j < k - 1){ printf(" "); } } return 0; } //······································· int BinSearch(int num[],int len,int key) { int low=0; //定义初始最小 int high=len-1; //定义初始最大 int mid; //定义中间值 while(low<=high) { mid=(low+high)/2; //找中间值 if(key==num[mid]) //判断min与key是否相等 return mid + 1; else if(key>num[mid]) //如果key>mid 则新区间为[mid+1,high] low=mid+1; else //如果key<mid 则新区间为[low,mid-1] high=mid-1; } return 0; //如果数组中无目标值key，则返回 0 ； }