# [luoguP2224] [HNOI2001]产品加工（背包DP）

f[i][j]表示第一个机器耗时j，第二个机器耗时f[i][j]

#include <cstdio>
#include <cstring>
#include <iostream>
#define INF 1e9
#define min(x, y) ((x) < (y) ? (x) : (y))
#define max(x, y) ((x) > (y) ? (x) : (y))

using namespace std;

int n, m, now = 0, last = 1, ans = 1e9;
int f[2][30011];

{
int x = 0, f = 1;
char ch = getchar();
for(; !isdigit(ch); ch = getchar()) if(ch == '-') f = -1;
for(; isdigit(ch); ch = getchar()) x = (x << 1) + (x << 3) + ch - '0';
return x * f;
}

int main()
{
int i, j, x, y, z;
for(i = 1; i <= n; i++)
{
m += max(x, max(y, z));
if(!x) x = INF;
if(!y) y = INF;
if(!z) z = INF;
now ^= 1, last ^= 1;
memset(f[now], 127 / 3, sizeof(f[now]));
for(j = m; j >= 0; j--)
{
if(j >= x) f[now][j] = min(f[now][j], f[last][j - x]);
f[now][j] = min(f[now][j], f[last][j] + y);
if(j >= z) f[now][j] = min(f[now][j], f[last][j - z] + z);
}
}
for(i = m; i >= 0; i--)
ans = min(ans, max(i, f[now][i]));
printf("%d\n", ans);
return 0;
}


posted @ 2018-01-20 07:16  zht467  阅读(96)  评论(0编辑  收藏