include <stdio.h>

int main()
{
printf(" O \n");
printf("\n");
printf("I I\n");
return 0;
}

任务二

include <stdio.h>

int main()
{
double a, b, c;
scanf_s("%lf%lf%lf", &a, &b, &c);
if((a + b > c) && (a + c > b) && (b + c > a))
printf("能构成三角形\n");
else
printf("不能构成三角形\n");
return 0;
}

任务三

include <stdio.h>

int main()
{
char ans1, ans2;
printf("每次课前认真预习、课后及时复习了没? (输入y或Y表示有，输入n或N表示没有) : ");
ans1 = getchar();
getchar();
printf("\n动手敲代码实践了没? (输入y或Y表示敲了，输入n或N表示木有敲) : ");
ans2 = getchar();
if ((ans1 == 'y' || ans1 == 'Y') && (ans2 == 'y' || ans2 == 'Y'))
printf("\n罗马不是一天建成的, 继续保持哦:)\n");
else
printf("\n罗马不是一天毁灭的, 我们来建设吧\n");
return 0;
}

任务四

include<stdio.h>

int main()
{
double x, y;
char c1, c2, c3;
int a1, a2, a3;
scanf_s("%d%d%d", &a1, &a2, &a3);
printf("a1 = %d, a2 = %d, a3 = %d\n", a1, a2, a3);
scanf_s("%c%c%c", &c1, &c2, &c3);
printf("c1 = %c, c2 = %c, c3 = %c\n", c1, c2, c3);
scanf_s("%lf,%lf", &x, &y);
printf("x = %f, y = %lf\n", x, y);
return 0;
}

任务五

include <stdio.h>

int main()
{
int year;
double total_second = 1000000000;
double second_per_year = 365.0 * 24 * 60 * 60;
year = (int)(total_second / second_per_year + 0.5);
printf("10亿秒约等于%d年\n", year);
return 0;
}

任务六

include <stdio.h>

include <math.h>

int main()
{
double x, ans;
scanf_s("%lf", &x);
ans = pow(x, 365);
printf("%.2f的365次方: %.2f\n", x, ans);
return 0;
}

任务七

include <stdio.h>

int main()
{
double celsius, fahrenheit;

printf("请输入多个摄氏温度值（输入非数字结束）：\n");
while (scanf_s("%lf", &celsius) == 1) {
    fahrenheit = (9.0 / 5.0) * celsius + 32;
    printf("摄氏度 c = %.2f 时，华氏度 f = %.2f\n\n", celsius, fahrenheit);
}

return 0;

}

任务八

include <stdio.h>

include <math.h>

int main()
{
double a, b, c, s, area;

printf("请输入多组三角形的三边边长（输入非数字结束）：\n");
while (scanf_s("%lf %lf %lf", &a, &b, &c) == 3) {
    s = (a + b + c) / 2.0;
    area = sqrt(s * (s - a) * (s - b) * (s - c));
    printf("三角形面积: %.3f\n\n", area);
}

return 0;

}