Sum of palindromic numbers

Description:

A number is called palindromic if its decimal representation is a palindrome. You are given a range, described by a pair of integers L and R. Find the sum of all palindromic numbers lying in the range [L, R], inclusive of both the extrema. Input The first line of the input contains an integer T denoting the number of test cases. The description of T test cases follows. The first line of each test case contains a pair of space separated integers L and R denoting the range for which you are required to find the sum of the palindromic numbers. Output For each test case, output a single line containing the sum of all the palindromic numbers in the given range. Constraints 1<=T<=100 Subtask 1 (34 points) : 1<=L<=R<=103 Subtask 2 (66 points) : 1<=L<=R<=105 Explanation Example case 1. The palindromic numbers between 1 and 10 are all numbers except the number 10. Their sum is 45. Test Case 1 Input (stdin) 2 1 10 123 150 Expected Output sum is 45 sum is 272 Test Case 2 Input (stdin) 5 1 10 12 30 100 200 50 60 250 300 Expected Output sum is 45 sum is 22 sum is 1460 sum is 55 sum is 1360

Program :

#define ull unsigned long long

#include <stdio.h>

#include <stdbool.h>

bool ispal(int n){

  int m=n,res=0;

  while(n){

    res*=10;

    res+=n%10;

    n/=10;

  }

  return res==m;

}

int main(){

  int t;

  scanf("%d",&t);

  while(t--){

    int i,min,max;

    ull res=0;

    scanf("%d%d",&min,&max);

    for(i=min;i<=max;i++){

      if(ispal(i)){

        res+=i;

      }

    }

    printf("sum is %lld\n",res);

  }

  return 0;

}