[user404 challenge #3]

2-dimensional, 1xn :P

Nah, you're right. Din engelsk er ok.

[user404 challenge #3]

Eh, what can you do... it's from 1998!

[User404 - Beginner Challenge #1]

yeah, i'm going through an old C book of exercises...

[user404 challenge #3]

problem 3:

find out from how many not falling sequences is the matrix made of

e.g.

4 32 5 1 2 6 7

answer 3

solution:

#include <stdio.h>

int main(void){
  int matrix[]={3,3,5,6,3,25,6,3,6,7,8,6}; //answer should be 5
  int counter=1;

  int i;
  for(i=1; i<sizeof(matrix)/sizeof(matrix[0]); i++){
    if(matrix[i-1]>matrix[i])
      counter++;
  }

  printf(" %d sequences\n", counter);

  return 0;
}

~
~
~
~

[user404 - challenge #2]

On to problem 2:

Given n, write a random permutation of numbers from 1 to n.

e.g. n=6

3 5 4 1 2 6

my solution:

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

#define MAX 50

int main(void){
  int n;
  int rand_matrix[MAX];
  int permutation[MAX];

  srand(time(NULL));

  printf(" n (max %d) = ", MAX); scanf("%d", &n);

  int i;
  for(i=0; i<n; i++){ //puts n random numbers in matrix
    rand_matrix[i]=rand();
  }

  int min_matrix=RAND_MAX;
  int min_i;
  int j=0;
  i=0;
  do{
    
    if(rand_matrix[i]<=min_matrix){ //have I found a smaller number?
      min_matrix=rand_matrix[i]; min_i = i;
    }

    i++;

    if(i==n){ //one cycle through the matrix
      permutation[j++]=min_i+1;
      rand_matrix[min_i]=RAND_MAX;

      //prepare for next cycle
      i=0;
      min_matrix=RAND_MAX;
    }
  }while(j<=n && j<MAX); 

  for(i=0; i<n; i++){
    printf(" %d", permutation[i]);
  }

  printf("\n");

  return 0;
}

[User404 - Beginner Challenge #1]

Hello!

I'm learning C, so I'll be posting the problems I'm solving here, join in if you want and post your solutions in your favorite language.

Challenge 1:

Write a program that reads numbers, until it reads 0, and then outputs them in reverse order.

Solution:

#include <stdio.h>

#define MAX 100

int main(void){
  int matrix[MAX];
  int num, i=0;

  printf(" Input at most %d integers, stop with 0\n", MAX);
  do{
    printf(" number[%d] = ", i); scanf("%d", &num);
    if(num==0) break;
    matrix[i]=num;
    i++;
  } while( i< MAX );

  while(i--) printf(" %d", matrix[i]);

  printf("\n");

  return 0;
}