task1_1.c

include <stdio.h>

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

printf(" O \n");


printf("<H>\n");
printf("I I\n");

return 0;

}

task1_2.c

include <stdio.h>

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

return 0;

}

task2.c

include <stdio.h>

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

}

task3.c

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表示没有敲):");
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;

}

当把源代码line9删除后，输入第一个y或者Y后，会直接输出结果从而跳过第二个字母的输入

task 4.c

include<stdio.h>

int main()
{
double x, y;
char c1, c2, c3;
int a1, a2, a3;

//scanf_s("%d%d%d", 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("%f%lf", &x, &y);
scanf_s("%lf%lf", &x, &y);
printf("x =%lf, y = %lf\n", x, y);
return 0;
}

task5.c

include<stdio.h>

int main()
{
int year;
long long seconds = 1000000000;
double years = seconds / 60.0 / 60.0 / 24.0 / 365.0;
int rounded_years = round(years);

printf("10亿秒约等于%d年\n", rounded_years);
return 0;

}

task6_2.c

include <stdio.h>

include <math.h>

int main()
{

double x, ans;

while (scanf_s("%lf", &x) != EOF)
{
    ans = pow(x, 365);
    printf("%.2f的365次方：%.2f\n", x, ans);
    printf("\n");
}

return 0;

}

task7.c

include <stdio.h>

int main()
{
double F, C;
while (scanf_s("%lf", &C) != EOF)
{
F = C * 9.0 / 5 + 32;
printf("摄氏度c =%.2lf时,华氏度f =%.2lf\n", C, F);
printf("\n");
return 0;
}

}

task 8.c

include <stdio.h>

include<math.h>

int main()
{
int a, b, c;
double s, area;
while (scanf_s("%d%d%d", &a, &b, &c) != EOF)
{
s = (a + b + c) / 2.0;
area = sqrt(s(s - a)(s - b) * (s - c));
printf("a=%d,b=%d,c=%d,aera=%.3lf\n", a, b, c, area);
printf("\n");
}
return 0;

}