UVA

来源：互联网发布：java zip压缩并加密编辑：程序博客网时间：2024/05/21 17:46

https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&problem=615

题意是有五种面值不同的硬币，每种都可以用无限个，问组合成给定价值有多少种组合方法

1.母函数求解，

#include<stdio.h>#include<iostream>#include<string.h>#include<math.h>#include<string>#include<algorithm>#include<queue>#include<vector>#include<map>#include<set>#define eps 1e-9#define PI 3.141592653589793#define bs 1000000007#define bsize 256#define MEM(a) memset(a,0,sizeof(a))#define inf 0x3f3f3f3f#define rep(i,be,n) for(i=be;i<n;i++)typedef long long ll;using namespace std;int a[10000],b[10000];int main(){int i,j,k,n,s[5]={1,5,10,25,50};a[0]=1;for(i=0;i<5;i++){for(j=0;j<=7500;j++){for(k=1;k*s[i]+j<=7500;k++)b[k*s[i]+j]+=a[j];}for(j=s[i];j<=7500;j++){a[j]=b[j];//保存上一层的系数 }}while(~scanf("%d",&n))printf("%d\n",a[n]);return 0; }

2.完全背包,递推状态，写法更简单

#include<stdio.h>#include<string.h>int dp[20000],n,i,j;int main(){memset(dp,0,sizeof(dp));dp[0]=1;int s[5]={1,5,10,25,50};for(i=0;i<5;i++){for(j=s[i];j<7500;j++){dp[j]+=dp[j-s[i]];}}while(~scanf("%d",&n)){printf("%d\n",dp[n]);}return 0;}

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