random_pattern.c

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
int main(){char t[100];scanf("%s",t);int l=strlen(t),x=l*3-3,y=l-1;for(int i=-y;i<=y;i++,printf("\n"))for(int j=x;j>=-x;j--){int m=abs(i+j),n=abs(i-j);printf("%c",(!m||m==(l-1)*3||!n||n==(l-1)*3||abs(i)==y&&(abs(j)>=l&&abs(j)<=(l-1)*2))?(abs(j)>=l*2-1?t[abs(m-n)/2]:t[abs(l-1-abs(j))]):' ');}return 0;}

/*
Input
programming

Output
          gnimmargorp                   programming
         n           r                 r           n
        i             o               o             i
       m               g             g               m
      m                 r           r                 m
     a                   a         a                   a
    r                     m       m                     r
   g                       m     m                       g
  o                         i   i                         o
 r                           n n                           r
p                             g                             p
 r                           n n                           r
  o                         i   i                         o
   g                       m     m                       g
    r                     m       m                     r
     a                   a         a                   a
      m                 r           r                 m
       m               g             g               m
        i             o               o             i
         n           r                 r           n
          gnimmargorp                   programming
------------------------------------------------------------
*/