SXCPC2018 nucoj2005 大闹上兰帝国

超 dark van♂全背包
ref1
ref2

#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
typedef long long ll;
int n, s, v[1005], w[1005], tmp[35], cnt ;
ll dp[4005], f[35][4005];
int main(){
	while(scanf("%d %d", &n, &s)!=EOF){
		memset(dp, 0, sizeof(dp));
		memset(f, 0, sizeof(f));
		cnt = 0;
		int maxv=0;
		for(int i=1; i<=n; i++){
			scanf("%d %d", &v[i], &w[i]);
			maxv = max(maxv, v[i]);
		}
		for(int i=1; i<=n; i++)
			for(int j=v[i]; j<=4*maxv; j++)
				dp[j] = max(dp[j], dp[j-v[i]]+w[i]);
		while(s>0){
			tmp[++cnt] = s;
			s = (s - maxv) >> 1;
		}
		for(int i=cnt; i; i--)
			for(int j=tmp[i]; j<=tmp[i]+2*maxv; j++)
				if(j<=4*maxv)
					f[i][j-tmp[i]] = dp[j];
				else{
					for(int k=(j-maxv)>>1; k<=j>>1; k++)
						f[i][j-tmp[i]] = max(f[i][j-tmp[i]], f[i+1][k-tmp[i+1]]+f[i+1][j-k-tmp[i+1]]);
				}
		printf("%lld
", f[1][0]);
	}
	return 0;
}