# Data structure and algorithm surface test questions 80 (21)

Source: Internet
Author: User

Enter two integers n and m, from series 1,2,3.......N take a few numbers in a random ,

Make it and equal to m, require that all possible combinations of them be listed

`//the essence of the problem is the 01 backpack, which just fills up. //because there are many groups of solutions, it is usually solved by recursion//for each n (n can be from N to 1)//if n is taken, then the sub-problem becomes find (n-1,m-n);//if n is not taken, then the sub-problem becomes find (n-1,m);#include<stdio.h>intLength//since the length of the flag is not good in the function, we set it as a global variablevoidFindcom (intNintMint*flag) {    if(n<1|| m<1)return;//boundary, the smallest number in the test instructions is 1    if(n>m) n=m;//pruning, greater than the number of m without consideration    if(n==m) {Flag[n-1]=1;//mark the last number as 1;//The number that will be marked as 1, the output         for(intI=0; i<length;i++)            if(flag[i]==1) printf ("%d\t", i+1); printf ("\ n"); Flag[n-1]=0;//Backtracking} flag[n-1]=1; Findcom (n-1, M-n,flag);//to nFlag[n-1]=0; Findcom (n-1, M,flag);//do not n}intMain () {intn,m; scanf ("%d%d",&n,&m); Length=n;//The n in the function is variable, so length is to be placed in main    intFlag[length];//Tag Arrayfindcom (N,m,flag); return 0;}`

Data structure and algorithm surface test questions 80 (21)

Related Keywords:

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

## A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

• #### Sales Support

1 on 1 presale consultation

• #### After-Sales Support

24/7 Technical Support 6 Free Tickets per Quarter Faster Response

• Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.