The number of divisions: the Blue Bridge

ALGO - 22. The number of divisions of

Problem Description

　　The integer n into k parts, and each can not be empty, any two can have the same ( without regard to order ) .

　　For example: n-=. 7, K =. 3, the three kinds of sub ⾯ method is considered to be the same.

　　1，1，5; 1，5，1; 5，1，1;

　　Q. How many different points system.

START input format

　　n，k

Output Format

　　⼀ integer, i.e., different sub-methods

Sample lose START

7 3

Sample Output

4 { four kinds of points of law: 1 , 1 , 5; 1 , 2 , 4; 1 , 3 , 3; 2 , 2 , 3;}

Data size and conventions. 6 <n-<= 200 is, 2 <= K <=. 6

Analysis: recursion, step represents the current number of remaining divided parts need ~~

The n into k parts, only the first frame number is equal to i, is calculated from i is equal to 1 until i is equal to n ⼀ / k, and the remaining k-1 ni is divided into the number of kinds of parts

…

⼀ number before the number of remaining front to be divided, each i from the front until the start ⼀ n / step ends, so as to ensure plan obtained

Points shutter mode is not diminishing, in order to ensure there will be no duplication of production ⽣ ~

#include <iostream>
using namespace std;
int   cnt = 0;
void  dfs( int front, int n, int step) {
      if( step == 1) {
          cnt++;
          return ;
      }
      for( int i = front; i <= n / step; i++)
           dfs(i, n - i, step - 1);
}
int main() {
    int n, k;
    cin >> n >> k;
    dfs(1, n, k);
    cout << cnt;
    return 0; 
}