CSU 1529: Equator(dp)

1529: Equator

Time Limit: 5 Sec Memory Limit:
128 MB

Submit: 419 Solved: 156

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Description

Input

Output

Sample Input

3
3 1 2 3
8 4 5 -1 -1 1 -1 -1 5
2 -1 -1

Sample Output

6
14
0

HINT

题意：给你n个数，按顺序接成一个环，求环的最大连续和。

题解：求出数列的最大连续和Max以及最小连续和Min，数列总和为sum，ans=max（sum-Min，Max）.

#include<set>
#include<map>
#include<queue>
#include<stack>
#include<ctime>
#include<deque>
#include<cmath>
#include<vector>
#include<string>
#include<cctype>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<sstream>
#include<iostream>
#include<algorithm>
#define REP(i,s,t) for(int i=(s);i<=(t);i++)
#define REP2(i,t,s) for(int i=(t);i>=s;i--)

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef unsigned long ul;

const int N=1000005;
int T;
int n;
int a
;
int main() {
    //freopen("test.in","r",stdin);
    scanf("%d",&T);
    while(T--) {
        scanf("%d",&n);
        int s=0;
        REP(i,1,n) {
            scanf("%d",&a[i]);
            s+=a[i];
        }
        int sum=0,ssum=0;
        int Max=0,Min=0;
        REP(i,1,n) {
            sum+=a[i];
            ssum+=a[i];
            if(sum<0) {
                sum=0;
            }
            if(sum>Max) {
                Max=sum;
            }
            if(ssum>0) {
                ssum=0;
            }
            if(ssum<Min) {
                Min=ssum;
            }
        }
        printf("%d\n",max(Max,s-Min));
    }
    return 0;
}