Simple Pattern 1

#include <stdio.h>

#define cls() printf("\033[H\033[J");

void main() {
  int row,line,width,dir=1;
  cls();
  for (row=1;row<11;row++) {
    for (line=0;line<=width;line++) {
      printf("@");
    }
    printf("\n");
    width+=dir;
    if (row==4) {dir=-1;}; //change direction
  }
}