UVa 357 Let Me Count The Ways Solution

#include<iostream>
#include<string>
#include<cstring>
#include<sstream>
#include<cctype>
#include<string.h>
#include<algorithm>
#include<cmath>
#include<stack>
#include<fstream>
#include<cstdlib>
#include<vector>
#include<map>
#include<utility>
#include<iomanip>
#include<queue>
#define eps 1e-9
#define max(a,b) ((a>b)?a:b)
#define min(a,b) ((a<b)?a:b)
#define pb(a) push_back(a)
#define mp(a,b) make_pair(a,b)
#define pi acos(-1.0)
#define CLR(a) memset(a,0,sizeof(a))
#define SET(a) memset(a,-1,sizeof(a))
#define pi acos(-1.0)

using namespace std;

long long coin[5]={1,5,10,25,50};
long long dp[5][30010];
long long func(long long prev,long long m)
    {
    if(m==0) return 1;
    if(m<0) return 0;
    if(dp[prev][m]!=-1) return dp[prev][m];
    dp[prev][m]=0;
    for(long long i=prev;i<5;i++)
        {
        if((m-coin[i])<0) continue;
        dp[prev][m]+=func(i,(m-coin[i]));
        }
    return dp[prev][m];
    }

int main()
{
long long n;
long long ans;
SET(dp);
while(cin>>n)
    {
    ans=func(0,n);
    if(ans==1) cout<<"There is only 1 way to produce "<<n<<" cents change."<<endl;
    else cout<<"There are "<<ans<<" ways to produce "<<n<<" cents change."<<endl;
    }
return 0;
}