小Q学习状态

 

     题目要求找到数组中某一段最小值与该段所有值和的乘积的最大值。利用动态规划，将问题分解为将数组截取三段，取其最大值，分别为全部值、去掉数组最小值后左半部分、去掉数组最小值右左半部分。AC80，超时

#include <map>  
#include <cmath>  
#include <queue>  
#include <cstdio>  
#include <string>  
#include <cstring>  
#include <iostream>  
#include <algorithm> 
#include <sstream> 
#include <time.h> 
#include <vector>
#include <list>
#include<iomanip>
#include<time.h>  

#define N_MAX 205
#define INF (0x3f3f3f3f)

using namespace std;
long long Data[100001] = { 0 };
bool Flag[100001] = { 0 };
int N_min = 0;
int N;
int find_min(int s, int e)
{
	int M = INF, k =s;
	for (int i = s; i <= e; ++i)
	{
		if (Data[i] < M)
		{
			M = Data[i];
			k = i;
			//cout << i;
		}
	}
	return k;
}
long long Cal(int s, int e)
{
	if (s > e )
		return 0;
	if (s == e)
		return Data[s] * Data[s];
	long long M = 0;
	for (int i = s; i <= e; ++i)
	{
		M += Data[i];
	}
	int k = find_min(s, e);
	M = M * Data[k];
	//cout << M << endl;
	M = max(max(Cal(s, k - 1), Cal(k + 1, e)), M);
	return M;
}

int main()
{
	cin >> N;
	for (int i = 0; i < N; ++i)
	{
		cin >> Data[i];
	}
	cout <<  Cal(0, N);
	return 0;
}