利用二分法,實如今一組有序數中尋找指定數字的下標ide
#define _CRT_SECURE_NO_WARNINGS 1 #include<stdio.h> int main() { int arr[10] = { 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 }; int k = 6; int sz = sizeof(arr) / sizeof(arr[0]);//計算元素個數 int left = 0;//左範圍 int right = sz - 1;//右範圍 while (left<=right) { int mid = (left + right) / 2; if (arr[mid] < k) { left = mid + 1; } else if (arr[mid] > k) { right = mid + 1; } else { printf("找到了,下表是%d\n", mid); break; } if (left > right) { printf("找不到\n"); } } return 0; }//實如今一組有序數中尋找指定數字的下標