C语言 从1打印到100再打印到1

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

int main()
{
	int a = 1;
	while (a <= 100) {
		printf("%d\n", a);
		a = a + 1;
	}
	a = 100;
	while (a >= 1) {
		printf("%d\n", a);
		a = a - 1;
	}
	system("pause");
	return 0;
}