POJ 3181 Dollar Dayz DP
f[i][j]=f[i-j][j]+f[i][j-1],结果很大需要高精度。
//#pragma comment(linker, "/STACK:1024000000,1024000000") #include<cstdio> #include<cstring> #include<cstdlib> #include<algorithm> #include<iostream> #include<sstream> #include<cmath> #include<climits> #include<string> #include<map> #include<queue> #include<vector> #include<stack> #include<set> using namespace std; typedef long long ll; typedef unsigned long long ull; typedef pair<int,int> pii; #define pb(a) push(a) #define INF 0x1f1f1f1f #define lson idx<<1,l,mid #define rson idx<<1|1,mid+1,r #define PI 3.1415926535898 template<class T> T min(const T& a,const T& b,const T& c) { return min(min(a,b),min(a,c)); } template<class T> T max(const T& a,const T& b,const T& c) { return max(max(a,b),max(a,c)); } void debug() { #ifdef ONLINE_JUDGE #else freopen("in.txt","r",stdin); //freopen("d:\\out1.txt","w",stdout); #endif } int getch() { int ch; while((ch=getchar())!=EOF) { if(ch!=' '&&ch!='\n')return ch; } return EOF; } const int MAX_LEN=20; const int BASE=100000; struct BigInt { int bit[MAX_LEN]; int len; BigInt(int n=0) { bit[0]=n; len=1; } BigInt operator + (const BigInt &ant) { int next=0; for(int i=0;i<len||i<ant.len;i++) { bit[i]=(i<len?bit[i]:0)+(i<ant.len?ant.bit[i]:0)+next; next=bit[i]/BASE; bit[i]%=BASE; } len=max(len,ant.len); if(next)bit[len++]=next; return *this; } void output() { printf("%d",bit[len-1]); for(int i=len-2;i>=0;i--) printf("%05d",bit[i]); printf("\n"); } }; BigInt dp[1005][105]; BigInt f(int n,int k) { if(n==0)return BigInt(1); if(k==1)return BigInt(1); if(n<k)return f(n,n); if(dp[n][k].len!=1||dp[n][k].bit[0]!=0)return dp[n][k]; dp[n][k]=f(n-k,k)+f(n,k-1); return dp[n][k]; } int main() { int n,k; while(scanf("%d%d",&n,&k)!=EOF) { for(int i=0;i<=n;i++) for(int j=0;j<=k;j++) dp[i][j]=BigInt(0); f(n,k); dp[n][k].output(); } return 0; }