ZOJ 1078 : Palindrom Numbers

zoj_1078.c

#include <stdio.h>
int base[16];

int palindrom(int len) {
	int i,j;
	for(i = 0,j = len-1; i < j; ++i, --j) {
		if (base[i] != base[j])
			return 0;
	}
	return 1;
}
int convert_base(int num, int b) {
	int len = 0;
	while(num != 0) {
		base[len] = (num%b);
		num /= b;
		len++;
	}
	return len;
}

int main() {
	int num, i, has;
	
	scanf("%d", &num);
	while(num != 0) {
		has = 0;
		for(i = 2; i <= 16; ++i) {
			if (palindrom(convert_base(num, i))) {
				has++;
				if(has == 1)
					printf("Number %d is palindrom in basis %d", num,i);
				else 
					printf(" %d", i);
			}
		}
		if (!has) {
			printf("Number %d is not a palindrom", num);
		}
		printf("\n");
		scanf("%d", &num);
	}
	return 0;
}