杭电OJ-Max Sum&&Max Sum Plus Plus（DP）

#include<iostream>//d[i]=max(d[i-1]+a[i],a[i]),a[i]要么是以第i个结尾的头，要么是以第i个结尾的尾
#include<cstring>
#include<algorithm>
#define inf 0x3f3f3f3f
using namespace std;
int a[100001];
int dp[100001];
int main() {
	int t;
	int n;
	cin >> t;
	for (int i = 1; i <= t; i++) {
		cin >> n;
		for (int i = 0; i <= n; i++) {
			dp[i] = -1001;
		}
		memset(a, 0, sizeof(a));
		for (int i = 1; i <= n; i++) {
			cin >> a[i];
		}
		int start, end;
		int max0 = -1001;
		for (int i = 1; i <= n; i++) {
			dp[i] = max(dp[i - 1] + a[i], a[i]);
			if (dp[i] > max0) {
				max0 = dp[i];
				end = i;
			}
		}
		int sum = 0;
		for (int i = end; i > 0; i--) {
			sum += a[i];
			if (sum == max0)
				start = i;
		}
		printf("Case %d:\n", i);
		printf("%d %d %d\n", max0, start, end);
		if (i < t)
			printf("\n");
	}
	return 0;
}









//dp[j]表示分成i组时，以第j个结尾的pair sum的最大值
#include<iostream>
#include<algorithm>
#include<cstring>
#define inf 0x3f3f3f3f
using namespace std;
int a[1000001];
int dp[1000001];
int Max[1000001];
int main() {
	int m, n,mmax;
	while (cin >> m >> n) {
		for (int i = 1; i <= n; i++) {
			cin >> a[i];
		}
		memset(Max, 0, sizeof(Max));
		memset(dp, 0, sizeof(dp));
		for (int i = 1; i <= m; i++) {
			mmax = -inf;
			for (int j = i; j <= n; j++) {
				dp[j] = max(dp[j - 1] + a[j], Max[j - 1] + a[j]);
				Max[j - 1] = mmax;
				mmax = max(mmax, dp[j]);
			}
		}
		cout << mmax <<endl;
	}
	return 0;
}