Example integer overflow

integer_overflow.c

#include <stdio.h>
//http://phrack.org/issues/60/10.html
//https://www.geeksforgeeks.org/maximum-value-of-unsigned-short-int-in-c/

//gcc -o integer_overflow integer_overflow.c
 int main(){
    unsigned short s;
    int i,j;
    
    printf("Please input [1-666]:");
    scanf("%d",&i);

    //triger the integer overflow  (When this value is transferred into the short integer s, 
    //it is truncated if the value is too great to fit into s (i.e. if the value is greater than 65535)    
    s = i;

    j = 666;
    if(s >= j){
        printf("You can't input more than %d\n",j);
        return -1;
    }
    
    if(s == (j-1)) { //66201
        printf("congratulations win :)\n");
    }else{
        printf("Sorry %d is not your lucky number\n", s);
    }

    return 0;
}

/*
longcat@kucingliar$gcc -o integer_overflow integer_overflow.c
longcat@kucingliar$./integer_overflow
Please input [1-666]:-1
You can't input more than 666
longcat@kucingliar$./integer_overflow
Please input [1-666]:100
Sorry 100 is not your lucky number
longcat@kucingliar$./integer_overflow
Please input [1-666]:6777
You can't input more than 666
longcat@kucingliar$./integer_overflow
Please input [1-666]:66201
congratulations win :)
*/