Untitled

#include<stdio.h>
#include<stdlib.h>
#include<time.h>

int main() //產生四位亂數 
{
	srand(time(0));
	
	int i, j, n[4];
	for (i=1;i<=4;i++){
		do{
			n[i-1] = rand() % 10;
			for (j = 1; j < i; j++){
				if(n[i-1] == n[j-1]){
					break;
				}
			}
		} while (j != i);
		printf("%d",n[i-1]);
	}
	printf("\n");
	return 0;
}