二分查找

#include<stdio.h>

int main() {
  int arr[] = { 1,2,3,4,5,6,7,8,9,10 };
  int left = 0;
  int max = sizeof(arr) / sizeof(arr[0]);
  int right = max - 1;
  int x = 0;
  printf("输入你想要查询的数值：");
  scanf_s("%d", &x);
  while (left <= right) {
    int mid = (left + right) / 2;
    if (arr[mid] == x) {
      printf("%d在数组中第%d个位置上", x, mid + 1);
      break;
    }
    else if (arr[mid] < x) {
      left = mid + 1;
    }
    else {
      right = mid - 1;
    }
  }
  if (left > right) {
    printf("未能找到该数值");
  }
  return 0;
}