十进制转换为二进制,不明白为什么i=n-1而不是i=n
#include <stdio.h>
#include<stdlib.h>
int main()
{
int num;
int n = 0;
int arr[100];
scanf("%d", &num);
while (num != 0)
{
arr[n++] = num % 2;
num = num / 2;
}
for (int i =n-1; i>=0; --i)
{
printf("%d", arr[i]);
}
system("pause");
return 0;
}