C program to convert binary to octal

#include<stdio.h>
#define MAX 1000
int main(){
   
    char octalNumber[MAX];
    long int i=0;

    printf("Enter any octal number: ");
    scanf("%s",octalNumber);

    printf("Equivalent binary value: ");
    while(octalNumber[i]){
        switch(octalNumber[i]){
             case '0': printf("000"); break;
             case '1': printf("001"); break;
             case '2': printf("010"); break;
             case '3': printf("011"); break;
             case '4': printf("100"); break;
             case '5': printf("101"); break;
             case '6': printf("110"); break;
             case '7': printf("111"); break;
             default:  printf("\nInvalid octal digit %c ",octalNumber[i]); return 0;
    }
    i++;
 }

    return 0;
}