p1474 Money Systems

就是背包，用O(n*m)的一维。

#include <iostream>
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cstring>
#include <map>
#include <queue>
#include <set>
#include <cassert>
#include <stack>
#include <bitset>
#define mkp make_pair
using namespace std;
const double EPS=1e-8;
typedef long long lon;
const lon SZ=10030,INF=0x7FFFFFFF,mod=9901;
lon dp[SZ],val[SZ];

int main()
{
    std::ios::sync_with_stdio(0);
    //freopen("d:\\1.txt","r",stdin);
    lon casenum;
    //cin>>casenum;
    //for(lon time=1;time<=casenum;++time)
    {
        int n,dst;
        cin>>n>>dst;
        for(int i=1;i<=n;++i)
        {
            cin>>val[i];
        }
        dp[0]=1;
        for(int i=1;i<=n;++i)
        {
            for(int j=1;j<=dst;++j)
            {
                if(j>=val[i])dp[j]+=dp[j-val[i]];
            }
        }
        //for(int i=1;i<=dst;++i)cout<<dp[i]<<endl;
        cout<<dp[dst]<<endl;
    }
    return 0;
}