[01背包] hdu1171

题目

有一个数组，要把他们分成两堆使其差值最小，求两堆的val

思路

呜呜呜居然是01背包，求dp[sum/2]就好了

代码

#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
#include<cctype>
#include<ctime>
#include<iostream>
#include<string>
#include<map>
#include<queue>
#include<stack>
#include<set>
#include<vector>
#include<iomanip>
#include<list>
#include<bitset>
#include<sstream>
#include<fstream>
#include<complex>
#include<algorithm>
#if __cplusplus >= 201103L
#include <unordered_map>
#include <unordered_set>
#endif
#define ll long long
using namespace std;
const int INF = 0x3f3f3f3f;
int dp[300010];
int main(){
	ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);
	int n;
	while(cin>>n){
		if(n<0) break;
		vector<int> v;
		memset(dp,0,sizeof dp);
		int sum=0;
		for(int i=1;i<=n;i++){
			int w,m;
			cin>>w>>m;
			while(m--) v.push_back(w),sum+=w;  
		}
		for(int i=0;i<v.size();i++){
			for(int j=sum/2;j>=v[i];j--){
				dp[j]=max(dp[j],dp[j-v[i]]+v[i]);
			}
		}
		cout<<sum-dp[sum/2]<<" "<<dp[sum/2]<<endl;
	}
	
    return 0;
}