一.题目链接:

HDU-3244

二.题目大意:

有 n 种原料,每种原料有 6 个属性.

x:每个人需要此原料的量

y:已有的量

s1:小包原料的数量

p1:小包原料的价钱

s2:大包原料的数量

p2:大包原料的价钱

现有 m 元,求最多的人数.

三.分析:

二分人数,check(mid) 函数里面对每种原料完全背包.

其中背包容量应设为 mid * x - y + s2 (+ s2 是因为可能买完之后不正好,但价格更低)

还有要各种控制边界,一不小心就会 TLE.

详见代码.

四.代码实现:

#include <set>
#include <map>
#include <ctime>
#include <queue>
#include <cmath>
#include <stack>
#include <bitset>
#include <vector>
#include <cstdio>
#include <sstream>
#include <cstring>
#include <cstdlib>
#include <iostream>
#include <algorithm>
#define eps 1e-8
#define lc k * 2
#define rc k * 2 + 1
#define pi acos(-1.0)
#define ll long long int
using namespace std;

const int M = (int)1e2;
const ll mod = (ll)1e9 + 7;
const int inf = 0x3f3f3f3f;

struct node
{
    int x, y;
    int s1, p1;
    int s2, p2;
}s[M + 5];

int dp[(int)6e6 + 5];

int n, m;

int cal_c(int k, int need)
{
    int w[2] = {s[k].s1, s[k].s2};
    int v[2] = {s[k].p1, s[k].p2};
    dp[0] = 0;
    int V = need + s[k].s2;
    for(int i = 1; i <= V; ++i)///这里只能赋初值到 V,不然就T了~
        dp[i] = inf;
    for(int i = 0; i < 2; ++i)
    {
        for(int j = w[i]; j <= V; ++j)
            dp[j] = min(dp[j], dp[j - w[i]] + v[i]);
    }
    int ans = inf;
    for(int i = need; i <= V; ++i)
        ans = min(ans, dp[i]);
    return ans;
}

bool check(int mid)
{
    int c = 0;
    int num;
    for(int i = 1; i <= n; ++i)
    {
        num = mid * s[i].x - s[i].y;
        if(num <= 0)
            continue;
        c += cal_c(i, num);
        if(c > m)
            return 0;
    }
    return 1;
}

int main()
{
    while(~scanf("%d %d", &n, &m) && (n + m))
    {
        for(int i = 1; i <= n; ++i)
            scanf("%d %d %d %d %d %d", &s[i].x, &s[i].y, &s[i].s1, &s[i].p1, &s[i].s2, &s[i].p2);
        int l = 0;
        int r = (int)1e5;
        while(l < r)
        {
            int mid = (l + r + 1) >> 1;
            if(check(mid))
                l = mid;
            else
                r = mid - 1;
        }
        printf("%d\n", r);
    }
    return 0;
}