Why I get very huge output in printf on C language? - c

Question

This is my code, I want to calculate distance between robot and monster, but the output "horizontal and vertikal" is false
#include <stdio.h>
void findPos(char *dir, int a, int b)
{
int up = 0, down = 0;
int left = 0, right = 0;
int i,x,y;
for (i = 0; dir[i] != '\0' ; i++) {
//Counts each direction
if (dir[i] == 'U' || dir[i] == 'u')
up++;
else if (dir[i] == 'D' || dir[i] == 'd')
down++;
else if (dir[i] == 'L' || dir[i] == 'l')
left++;
else if (dir[i] == 'R' || dir[i] == 'r')
right++;
//In case of illegal character in the string
else
{
printf("Position Unable to Find, Enter Correct Direction.");
break;
}
}
//Final position of robot
x = right - left;
y = up - down;
printf("Final Position of the Robot: (");
printf("%d", x);
printf(",%d", y);
print(")");
printf("\nposition between robot and monster");
printf("\nhorizontal: %d", a-x);
printf("\nvertikal: %d", b-y);
}
int main()
{
char *dir;
int a,b,t;
/* Intializes random number generator */
srand((unsigned) time(&t));
/* Print 2 random numbers from 0 to 100 */
a = rand() % 100;
b = rand() % 100;
printf("\nCoordinate of monster: ");
printf("(%d,", a);
printf("%d)", b);
//Input the direction string
printf("\nEnter the Direction String: ");
scanf("%s", &dir);
//Function call to calculate position
findPos(&dir, a,b);
return 0;
}
and this is the output
Coordinate of monster: (5,47)
Enter the Direction String: UURRRRRLLL
Final Position of the Robot: (2,2)
position between robot and monster
horizontal: 19530
vertikal: 1280463440

Answer 1

it seems your program is exhibiting undefined behavior, you are actually lucky its not crashing, dir is never allocated . you might want to calloc it before using , also remove the & in scanf, infact move to fgets unless inclined to use scanf
printf("\nEnter the Direction String: ");
scanf("%s", dir);