Eddy‘s research II

As is known, Ackermann function plays an important role in the sphere of theoretical computer science. However, in the other hand, the dramatic fast increasing pace of the function caused the value of Ackermann function hard to calcuate.

Ackermann function can be defined recursively as follows:


Now Eddy Gives you two numbers: m and n, your task is to compute the value of A(m,n) .This is so easy problem,If you slove this problem,you will receive a prize(Eddy will invite you to hdu restaurant to have supper).

1 3
2 4

5
11

附个代码：

#include<stdio.h>
#include<string.h>
#include<algorithm>
#include<iostream>
#include<queue>
#include<map>
using namespace std;
#define N 1000005
#define ll __int64
const int inf=0x7fffffff;
int f[4][N];       //A(m,n)
/*void inti()
{
    int i;
    memset(f,-1,sizeof(f));
    for(i=0;i<N;i++)
        f[0][i]=i+1;

}
int solve(int m,int n)
{
    if(f[m][n]!=-1)
        return f[m][n];
    if(m==0)
        return n+1;
    if(n==0)
        return f[m][n]=solve(m-1,1);
    return f[m][n]=solve(m-1,solve(m,n-1));
}
int main()
{
    inti();
    int m,n;
    while(scanf("%d%d",&m,&n)!=-1)
    {
        printf("%d\n",solve(m,n));
    }
    return 0;
}*/
int fun(int i)
{
    if(i==0)
        return 5;
    if(i==1)
        return 13;
    return 15;
}
void inti()
{
    int i,t;
    for(i=0;i<N;i++)
        f[0][i]=i+1;
    for(i=0;i<N;i++)
        f[1][i]=i+2;
    for(i=0;i<N;i++)
        f[2][i]=i*2+3;
    f[3][0]=5;
    for(i=1,t=8;i<30;i++)
    {
        f[3][i]=f[3][i-1]+t;
        t*=2;
    }
}
int main()
{
    int m,n;
    inti();
    while(~scanf("%d%d",&m,&n))
        printf("%d\n",f[m][n]);

    return 0;
}

hdu 1165 Eddy's research II(递推+打表)

原文：http://blog.csdn.net/u011721440/article/details/44673741