## 01-复杂度2 Maximum Subsequence Sum （25 分)

Given a sequence of

Now you are supposed to find the largest sum, together with the first and the last numbers of the maximum subsequence.

### Input Specification:

Each input file contains one test case. Each case occupies two lines. The first line contains a positive integer

### Output Specification:

For each test case, output in one line the largest sum, together with the first and the last numbers of the maximum subsequence. The numbers must be separated by one space, but there must be no extra space at the end of a line. In case that the maximum subsequence is not unique, output the one with the smallest indices

### Sample Input:

10
-10 1 2 3 4 -5 -23 3 7 -21


### Sample Output:

10 1 4
#include<cstdio>
const int maxn = 100100;
int a[maxn] = {0};
int dp[maxn] = {0};
int s[maxn] = {0};

int main(){
int n;
scanf("%d",&n);
bool flag = false;
for(int i = 0; i < n; i++){
scanf("%d",&a[i]);
if(a[i] >= 0) flag = true;
}
if(!flag){
printf("0 %d %d",a,a[n-1]);
return 0;
}
//scanf("%d",&n);
dp = a;
for(int i = 1; i < n; i++){
if(dp[i-1] + a[i] >= a[i]){
dp[i] = dp[i-1]+a[i];
s[i] = s[i-1];
}else{
dp[i] = a[i];
s[i] = i;
}
}
int max = dp;
int k = 0;
for(int i = 1; i < n; i++){
if(dp[i] > max){
max = dp[i];
k = i;
}
}
printf("%d %d %d",max,a[s[k]],a[k]);
return 0;
}

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