<JZOJ1286>太空电梯

一道简单可爱的dp

#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
#define max(a,b) (a>b?a:b)
#define rint register int
using std::sort;
using std::cout;
using std::endl;
template <class T>inline void read(T &X)
{
    X=0;int W=0;char ch=0;
    while(!isdigit(ch))W|=ch=='-',ch=getchar();
    while(isdigit(ch))X=(X<<3)+(X<<1)+(ch^48),ch=getchar();
    X=W?-X:X;return;
}

int n,dp[16000000]={0},ans=0;
struct node{int h,a,c;}e[410];
int cmp(node x,node y){return x.a<y.a;}
int main()
{
    read(n);
    for(rint i=1;i<=n;++i)read(e[i].h),read(e[i].a),read(e[i].c);
    sort(e+1,e+n+1,cmp);

    dp[0]=1;
    for(rint i=0;i<=n;++i)
    {
        for(rint j=e[i].a;j>=0;--j)
        {
            if(dp[j])
            {
                for(rint k=1;k<=e[i].c;++k)
                {
                    if(j+k*e[i].h>e[i].a)break;
                    dp[j+k*e[i].h]=1;
                }
            }
        }
    }
    for(rint i=e[n].a;i>=0;--i)
        if(dp[i]){printf("%d\n",i);break;}
return 0;
}