#include <stdio.h>
#include <stdlib.h>
int main()
{
int time, min, sec;
for(time = 120; time >= 0; --time){
system("cls");
min = time / 60;
sec = time % 60;
printf("%d:%.2d", min, sec);
sleep(1000);
}
int main(void)
{
int i, sum;
sum = 0;
for( i = 2; i <= 100; i+=2)
sum += i;
printf("%d\n",sum);
system("pause");
return 0;
}
第二题的问题在于,你没有检验n是否在1和9之间,所以应该这么改一下
#include <stdio.h>
#include <stdlib.h>
int main(void)
{
int result, a, i;
result = 1;