C Exercises: Find all prime palindromes in the range of two given numbers x and y

C Basic Declarations and Expressions: Exercise-90 with Solution

Write a C program to find all prime palindromes in the range of two given numbers x and y (5 <= x<y<= 1000,000,000).
A number is called prime palindrome if the number is both a prime number and a palindrome.

Sample Solution:

C Code:

#include<stdio.h>

int compute(int n){
	if(n==9)
		return 11;
	int res = 0,tmp,base = 1;
	for(tmp = n/10;tmp>0;tmp = tmp/10){
		res = res*10 + tmp % 10;
		base *= 10;
	}
	return n* base + res;
}

int prime(int n){
	int i;
	int flag;
	for(i = 2;i*i<= n;i++){
		flag = 0;
		if(n%i==0){
			flag = 1;
			break;
		}
		
	}
	if(flag == 0){
			printf("%d\n",n);
		}
}

main(){
	int x,y,temp = 0;
	printf("Input two numbers (separated by a space):\n");
	scanf("%d%d",&x,&y);
	printf("List of prime palindromes:\n");
	for(;temp <= y;x++){
		temp = compute(x);
		prime(temp);
	}
}

Sample Output:

Input two numbers (separated by a space):
List of prime palindromes:
0
1

Flowchart:

C programming Code Editor:

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