How can i print a pyramid using C?-CodePudding

I am using C in this case and its my first time creating multiples nested loops.

Let us consider this problem:

I wrote this program :

#include <stdio.h>
int main() {
  int n = 9;
  int p = n   1;
  int q = p / 2;
  for (int i = 1; i <= q; i  ) {
    for (int j = i; j <= q; j  ) {
      printf(" ");
    }
    for (int k = 1; k <= i; k  ) {
      printf("8");
    }
    printf("\n");
  }
  for (int o = q   1; o <= n; o  ) {
    for (int l = 1; l <= o; l  ) {
      printf(" ");
    }
    for (int m = o; m <= n; m  ) {
      printf("8");
    }
    printf("\n");
  }
}

Instead of creating a pyramid, it is creating something that looks like this:

What should i do to fix this?

CodePudding user response：

int main() {
  int n = 9;
  int p = n   1;
  int q = p / 2;
  for (int i = 1; i <= q; i  ) {
    for (int j = i; j <= q; j  ) {
      printf(" ");
    }
    for (int k = 1; k <= i; k  ) {
      printf("8");
    }
    printf("\n");
  }
  for (int o = q   1; o <= n; o  ) {
    for (int l = 1; l <= o - q   1; l  ) {
      printf(" ");
    }
    for (int m = o; m <= n; m  ) {
      printf("8");
    }
    printf("\n");
  }
}

https://godbolt.org/z/cPW14b5W1

CodePudding user response：

You're using almost the entire lowercase alphabet as variable names... Who wants to keep track of all of that?

Two variables (one int and one string) suffice...

int main() {
    int i;
    char *out = "     88888";
    i = 1; while( i < 5 ) printf( "%.5s\n", out   0   i   );
    i = 0; while( i < 5 ) printf( "%.5s\n", out   5 - i   );
    return 0;
}

Code should be clear & concise. Your readers will thank you...

EDIT
A comment by the OP below the OP suggests that this function should not be limited to 5 characters width.
Once the fundamental (short) code is written, it can be generalised.

int main() {
    int i;
    for( int n = 2; n <= 9; n   ) {
        char *out = malloc( n   n ); // don't need/use '\0'...
        /* Omitting test for failure */
        memset( out   0, ' ', n );
        memset( out   n, n   '0', n );
        i = 1; while( i < n ) printf( "%.*s\n", n, out   0   i   );
        i = 0; while( i < n ) printf( "%.*s\n", n, out   n - i   );
        printf( "=======" ); getchar();
        free( out );
    }
    return 0;
}