裸0/1背包,就是从各种币种里面拿来凑足N元,求最多有多种方案。用dp[i][j]表示选前i个币种凑成j的方案数量
状态转移方程: dp[i][j] = dp[i- 1][j] j < coins[i] dp[i][j] = dp[i-1][j] + dp[i-1][j-coins[i]] j >= coins[i]
/* ID:kevin_s1 PROG:money LANG:C++ */ #include <iostream> #include <cstdio> #include <string> #include <cstring> #include <vector> #include <map> #include <set> #include <algorithm> #include <cstdlib> #include <list> #include <cmath> using namespace std; #define MAXN 10010 //gobal variable==== int V; long long N; int coins[30]; long long dp[30][MAXN]; //================== //function========== //================== int main(){ freopen("money.in","r",stdin); freopen("money.out","w",stdout); cin>>V>>N; int coin; for(int i = 1; i <= V; i++){ cin>>coin; coins[i] = coin; } for(int i = 1; i <= V; i++) dp[0][i] = 0; dp[0][0] = 1; for(int i = 1; i <= V; i++){ for(long long j = 0; j < coins[i]; j++){ dp[i][j] = dp[i - 1][j]; } for(long long j = coins[i]; j <= N; j++){ dp[i][j] = dp[i - 1][j] + dp[i][j - coins[i]]; } } cout<<dp[V][N]<<endl; return 0; }
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原文地址:http://blog.csdn.net/kevin_samuel/article/details/36090451