hdu1003 Max Sum(最大子串)

https://vjudge.net/problem/HDU-1003

注意考虑如果全为负的情况，特判。

还有输出格式，最后一个输出不用再空行。

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cstdlib>
#include<cmath> 
#define lson l, m, rt<<1
#define rson m+1, r, rt<<1|1
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define INF 1e9
typedef long long ll;
using namespace std;
int n, m, a[100010];
int main()
{
    IO;
    cin >> n;
    int kase=0;
    while(n--){
        cin >> m;
        for(int i = 0; i < m; i++){
            cin >> a[i];
        }
        int sum = 0, maxm = -INF;
        int from = 0;
        int ans1 = 0, ans2 = -1;
        for(int i = 0; i < m; i++){
            sum += a[i];
            if(sum < 0){
                sum = 0;
                from = i+1;
            }
            else{
                if(sum > maxm){
                    maxm = sum;
                    ans1 = from;
                    ans2 = i;
                } 
            }
        }
        cout << "Case " << ++kase << ":" << endl;
        if(ans2 == -1){//sum一直小于零，每位<0   
            maxm = -INF;
            for(int i = 0; i < m; i++){
                if(a[i] > maxm){
                    maxm = a[i];
                    ans1 = i; ans2 = i;
                }
            }
            cout << maxm << " " << ans1+1 << " " << ans2+1 << endl;
        }
        else
            cout << maxm << " " << ans1+1 << " " << ans2+1 << endl;
        if(n != 0) cout << endl;
    }
    return 0;
}