題目
有一個升序排列的數組，數組中可能有正數，負數或0. 求數組中元素的絕對值最小的數.
例如 數組{-10， 05， 02 ，7，15，50} 絕對值最小的是-2
解答
#include <bits/stdc++.h>
using namespace std;void f(int a[], int len) {if (a[len-1] <= 0) {cout << abs(a[len-1]) <<endl;return ;}if (a[0] >= 0) {cout << a[0] << endl;return ;}// 有正有負int l = 0, r = len-1;while (l <= r) {int m = (l + r) / 2;if(a[m] == 0) {cout << a[m] << endl;return ;} else if(a[m] > 0) {if(a[m-1] < 0) {int mn = min(abs(a[m-1]), a[m]);cout<< mn <<endl;return ;} else if (a[m-1] == 0) {cout << 0 <<endl;return ;} else {// a[m-1] > 0r = m-1;}} else {// a[m] < 0if(a[m+1] > 0) {int mn = min(abs(a[m]), a[m+1]);cout << mn <<endl;return ;} else if(a[m+1] == 0) {cout << 0 <<endl;return ;} else {// a[m+1] < 0l = m+1;}}}return ;
}int main()
{int a1[] = {-10, -5, -2, 7, 15 ,50};int a2[] = {2,4,6,8,27};int a3[] = {-13, -9, -7, -3};int l1 = 6, l2 = 5, l3 = 4;f(a1, l1);f(a2, l2);f(a3, l3);return 0;
}
