Ignatius and the Princess III
Time Limit:1000MS Memory Limit:65536K
Total Submit:86 Accepted:66
Description
"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
The input contains several test cases. Each test case contains a positive integer N(1<=N<=120) which is mentioned above. The input is terminated by the end of file.
Output
For each test case, you have to output a line contains an integer P which indicate the different equations you have found.
Sample Input
4
10
20
Sample Output
5
42
627
就是这个题目上次我写整数划分的时候半天也没找到。。。直接用递归会超时!!
代买如下:
#include<cstdio>
int main()
{
int i,j,n,c[121][121];
for(i=1;i<121;i++)
for(j=1;j<121;j++)
{
if(i==1||j==1)
c[i][j]=1;
else if(i<j)
c[i][j]=c[i][i];
else if(i==j)
c[i][j]=c[i][j-1]+1;
else
c[i][j]=c[i][j-1]+c[i-j][j];
}
while(scanf("%d",&n)!=EOF)
{
printf("%d\n",c[n][n]);
}
return 0;
}
posted on 2010-09-19 13:59
jince 阅读(142)
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