POJ 1852 Ants O(n)

题目：

思路：蚂蚁相碰和不相碰的情况是一样的，相当于交换位置继续走。

代码：

#include <iostream>#include <cstdio>#include <math.h> using namespace std;typedef long long ll;int main() {    int t;    int l,n;    int key;    int low,high;    cin >> t;    while(t--){        cin >> l >> n;        int mn = 0;        int mx = 0;        for(int i = 0;i < n; i++){            scanf("%d",&key);            if(key < l/2){                low = key;                high = l-key;            }else{                low = l-key;                high = key;            }            mn = max(low,mn);            mx = max(high,mx);        }        cout << mn << " " << mx << endl;    }  return 0;}//  writen by zhangjiuding