写代码可以在整型有序数组中查找想要的数字, 找到了返回下标,找不到返回-1(折半查找/二分查找)
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <stdlib.h>
int main() {
int arr[] = { 1,2,3,4,5 };
int left = 0;
int right = sizeof(arr) / sizeof(arr[0]) - 1;
int key = 0;
printf("请输入想要找的数:");
scanf("%d", &key);
while (left <= right) {
int mid = left + (right - left) / 2;
if (arr[mid] > key) {
right = mid - 1;
}
else if (arr[mid] < key) {
left = mid + 1;
}
else {
printf("找到了下标为%d\n",mid);
return mid;
}
}
if (left > right) {
printf("找不到\n");
return -1;
}
system("pasue");
return 0;
}