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递归。。。
#include<stdio.h>
#include<string.h>
const int MAXN=130;
int dp[MAXN][MAXN];
int calc(int n,int m)
{
if(dp[n][m]!=-1) return dp[n][m];
if(n<1||m<1) return dp[n][m]=0;
if(n==1||m==1) return dp[n][m]=1;
if(n<m) return dp[n][m]=calc(n,n);
if(n==m) return dp[n][m]=calc(n,m-1)+1;
else
return dp[n][m]=calc(n,m-1)+calc(n-m,m);
}
int main()
{
int n;
memset(dp,-1,sizeof(dp));
while(scanf("%d",&n)!=EOF)
printf("%d\n",calc(n,n));
return 0;
}
Well, it seems the first problem is too easy. I will let you know how foolish you are later." feng5166 says.
"The second problem is, given an positive integer N, we define an equation like this:
N=a[1]+a[2]+a[3]+...+a[m];
a[i]>0,1<=m<=N;
My question is how many different equations you can find for a given N.
For example, assume N is 4, we can find:
4 = 4;
4 = 3 + 1;
4 = 2 + 2;
4 = 2 + 1 + 1;
4 = 1 + 1 + 1 + 1;
so the result is 5 when N is 4. Note that "4 = 3 + 1" and "4 = 1 + 3" is the same in this problem. Now, you do it!"
Input
Output
Sample Input
41020
Sample Output
542627