What is wrong in my code to calculate factorial of large numbers

#include<stdio.h> int a[100],n1,temp=0,i=0,c=0,x; void factorial(int); void print(); int main() { a[0]=1; printf("enter number to calculate factorial\n"); scanf("%d",&n1); for(i=2;i<=n1;i++) { factorial(i); } print(); return 0; } void factorial(int n2) { temp=0; printf("%d\n",a[0]); for(i=0;i<=c;i++) { x=a[i]*n2+temp; a[i]=x%10; temp=x/10; } while(temp!=0) { c++; a[c]=temp%10; temp=temp/10; } } void print() { for(i=c;i>=0;i--) { printf("%d",a[i]); } }