task1_1.c，

`#include <stdio.h>
int main()
{
int n;
for(n=1;n<3;n++){
printf(" O \n");
printf("\n");
printf("I I\n");
}

return 0;

}
`

task1_2.c

#include <stdio.h> int main() { printf(" O O \n"); printf("<H> <H>\n"); printf("I I I I\n"); return 0; }

task2.c

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; }

`#include<stdio.h>

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

scanf("%d %d %d",&a1,&a2,&a3);
printf("a1 = %d, a2 = %d, a3 = %d\n",a1,a2,a3);

scanf(" %c %c %c", &c1, &c2, &c3);
printf("c1 = %c, c2 = %c, c3 = %c\n",c1,c2,c3);

scanf("%lf %lf", &x, &y);
printf("x = %f, y = %lf\n",x,y);

return 0;
}
`

task5.c

#include <stdio.h> int main() { int year; double x=1e9/(365.25*24*60*60) +0.5; year=x; printf("10亿秒约等于%d年\n", year); return 0; }

task6_2.c

`#include <stdio.h>

include <math.h>

int main()
{
double x, ans;
while(scanf("%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("%lf",&c)!= EOF){
f=1.8*c+32;
printf("摄氏度C=%.2f时，华氏度F=%.2f\n",c,f);
}

return 0;

} `

task8.c

`#include<stdio.h>

include<math.h>

int main(){
double a,b,c,s,area;
while(scanf("%lf %lf %lf",&a,&b,&c)!= EOF){
s=(a+b+c)/2;
area=sqrt(s(s-a)(s-b)*(s-c));
printf("a=%f,b=%f,c=%f,area=%.3f\n",a,b,c,area);
}

return 0;

} `