bzoj1578 [Usaco2009 Feb]Stock Market 股票市场

传送门：http://www.lydsy.com/JudgeOnline/problem.php?id=1578

【题解】

由于连续买相当于每天买，第二天卖，然后再买。所以每天最后钱尽量多一定是最优的。

所以对于m天，每天做一次O(n*70w)的完全背包dp即可。

# include <stdio.h>
# include <string.h>
# include <iostream>
# include <algorithm>
// # include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
const int M = 7e5 + 10, N = 100 + 10;
const int mod = 1e9+7;

# define RG register
# define ST static

int n, m;
int f[N], w[N][N], g[M];

int main() {
    cin >> n >> m >> f[1];
    for (int i=1; i<=n; ++i)
        for (int j=1; j<=m; ++j) cin >> w[i][j];
    
    for (int i=2; i<=m; ++i) {
        int pre = 0, cur = 1;
        for (int k=0; k<=f[i-1]; ++k)
            g[k] = 0;
                
        for (int j=1; j<=n; ++j) 
            for (int k=0; k<=f[i-1]; ++k) 
                if(k >= w[j][i-1]) g[k] = max(g[k], g[k-w[j][i-1]] + w[j][i]);
        
        for (int k=0; k<=f[i-1]; ++k)
            if(g[k] + (f[i-1]-k) > f[i]) f[i] = g[k] + (f[i-1]-k);
    }
    cout << f[m];

    return 0;
}