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

 

 

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

return 0;
}

 

 

#include <stdio.h>
int main()

{
int x, y; 
int r1, r2, r3, r4; 
x = 1;
y = 2;
r1 = x + y;
r2 = x - y;
r3 = x * y;
r4 = x / y;
printf("r1 = %d\n", r1); 
printf("r2 = %d\n", r2); 
printf("r3 = %d\n", r3);
printf("r4 = %d\n", r4);
return 0;
}

 

#include <stdio.h>
int main()

{
float x, y; 
float r1, r2, r3, r4; 
x = 1;
y = 2;
r1 = x + y;
r2 = x - y;
r3 = x * y;
r4 = x / y;
printf("r1 = %f\n", r1); 
printf("r2 = %f\n", r2); 
printf("r3 = %f\n", r3);
printf("r4 = %f\n", r4);
return 0;
}

整形无法保存0.5，取整到0

 

 

#include <stdio.h>
int main()

{
int n, r1, r2, r3, r4;
n = 100;
r1 = n*(n+1)/2;
r2 = (n+1)*n/2;
r3 = n/2*(n+1);
r4 = (n+1)/2*n;
printf("n = %d\n", n);
printf("r1 = %d\n", r1);
printf("r2 = %d\n", r2);
printf("r3 = %d\n", r3);
printf("r4 = %d\n", r4);

return 0;
}

 

 

 

#include <stdio.h>
int main()

{
int n, r1, r2, r3, r4;
n = 101;
r1 = n*(n+1)/2;
r2 = (n+1)*n/2;
r3 = n/2*(n+1);
r4 = (n+1)/2*n;
printf("n = %d\n", n);
printf("r1 = %d\n", r1);
printf("r2 = %d\n", r2);
printf("r3 = %d\n", r3);
printf("r4 = %d\n", r4);

return 0;
}

1.n*(n+1)/2   2.n*(n+1)/2   3.(n/2)*(n+1)   4.((n+1)/2)*n

奇数除二要取整，偶数结果不变

 

 

#include <stdio.h>
int main()

{
double x,y;
char c1,c2,c3;
int a1,a2,a3;
scanf("%d%d%d",&a1,&a2,&a3);
printf("%d,%d,%d\n",a1,a2,a3);
scanf(" %c %c %c",&c1,&c2,&c3);
printf("%c,%c,%c\n",c1,c2,c3);
scanf("%lf%lf",&x,&y);
printf("%lf,%lf\n",x,y);

return 0;
}

 

 

#include <stdio.h>
int main()

{

int a1, a2;
char c1, c2;
scanf("%d %c %d %c", &a1, &c1, &a2, &c2);
printf("a1 = %d, a2 = %d\n", a1, a2);
printf("c1 = %c, c2 = %c\n", c1, c2);

return 0;
}

 

 

#include <stdio.h>
int main()

{
int answer;
char words[5000];
printf("网课学习让一些人欢喜一些人忧.\n");
printf("1. 作为一个宅，社恐，觉得这样很好. 有网络，自主学习，很ok.\n");
printf("2. 不喜，不喜，很不喜. 眼睛快瞎了. 脑壳有点卡...\n");
printf("3. 中间派. 不知道. 说不清.\n");
printf("4. 其它...\n");
printf("你的选择: ");
scanf("%d", &answer);
if(answer == 4) {
printf("请补充说明你的想法: \n");
getchar(); 
gets(words); 
}
printf("\n"); 
printf("当遇到问题时, 你会选择:\n");
printf("1. 遇到问题, 就解决问题。不懂的，搜索式学习，逐个攻破.\n");
printf("2. 遇到问题, 不高兴。然后,...,没有了.\n");
printf("3. 其它...\n");
printf("你的选择: ");
scanf("%d", &answer);
if(answer == 1)
printf(":)\n");
else if(answer == 2)
printf("这样不能解决问题啊...我们选择1好不好:)\n");
else if(answer == 3) {
printf("请补充说明你的想法: \n");
getchar(); 
gets(words); 
}
return 0;
}