学C语言的第三天30个练习
#define _CRT_SECURE_NO_WARNINGS#include <stdio.h>
#include<stdlib.h>
#include <math.h>
#define ok 0
#define PI 3.14//定义一个全局常量
int main01() {
printf("你好呀\n");
printf("小哥哥");
return 0;
}
int main02() {
//system("mspaint");
//system("calc");
//system("cmd");
//system("G://QQ浏览器下载//1.jpg");
//system("javac");
//system("C:/Windows10Upgrade/Windows10UpgraderApp.exe");
printf("123");
system("pause");
return 0;
}
int main03() {
int a = 1;
int b = 2;
int c = 3;
c = a + b;
printf("%d\n", c);
return 0;
}
int main04() {
char buff = "";
sprintf(buff, "5678");
printf("buff=%s",buff);
return 0;
}
int main05() {
const int b = 10;
extern int a;
int* p = &b;
printf("p=%x\n",p);
*p = 100;
printf("b=%d\n", b);
printf("%d\n",b);
int c= &b;
printf("%x\n",c);
scanf("%d\n", &b);
printf("%d\n",b);
return 0;
}
int main06() {
int r=0;
printf("请输入半径\n");
scanf("%d", &r);
printf("%d\n", r);
printf("%lf\n",r*PI*r);
return 0;
}
int main07() {
int num = 0x80000001;
//1000 0000 0000 0000 0000 0000 0000 0001
//反码1111 1111 1111 1111 1111 1111 1111 1110
//原码1111 1111 1111 1111 1111 1111 1111 1111-2147483647
printf("%d\n", num);
return 0;
}
int main08() {
int a = 10;
int b = 020;
int c = 0x89;
printf("a=%d\n", a);
printf("b=%o\n", b);
printf("c=%x\n", c);
printf("c=%#x\n", c);
printf("c=%#X\n", c);
return 0;
}
int main09() {
int a = 10;
//001 000
int b = 020;
//010 000
int c = 0x89;
//1000 1001
//12881
//十进制
printf("a=%d\n", a);
printf("b=%d\n", b);
printf("c=%d\n", c);
//八进制
/*
8 10
12
801
*/
printf("a=%o\n", a);
printf("b=%o\n", b);
/*
010 001 001
2 1 1
*/
printf("c=%o\n", c);
//十六进制
printf("a=%x\n", a);
/*
16 10
0 10A
*/
printf("b=%x\n", b);
/*
0001 0000
1 0
*/
printf("c=%x\n", c);
return 0;
}
int main10() {
char num = 0x81;
unsigned sum = 0x82;
//0000 0000 0000 0000 0000 0000 1000 0010
// 128 2
//1000 0001
//1111 1110
//1111 1111
printf("%d\n", num);//-127
printf("%ud\n", num);//4294967169d
printf("unsigned\n");
printf("%d\n", sum);//130
printf("%ud\n", sum);//130
return 0;
}
int main11() {
//定义无符号int变量d，以16进制方式赋值
unsigned int d = 0xffffffff;
// 1111 1111 1111 1111 1111 1111 1111 1111
//反码:1000 0000 0000 0000 0000 0000 0000 0000
//补码:1000 0000 0000 0000 0000 0000 0000 0001
printf("%d\n", d);
printf("%ud\n", d);
return 0;
}
int main12() {
printf("int=%d\n", sizeof(int));
printf("double=%d\n", sizeof(double));
printf("float=%d\n", sizeof(float));
printf("short=%d\n", sizeof(short));
printf("char=%d\n", sizeof(char));
printf("long=%d\n", sizeof(long));
printf("long long=%d\n", sizeof(long long));
return 0;
}
int main13() {
int a = 0;
int b = 0;
scanf("%d %d", &a, &b);
printf("%d\n", a);
printf("%d\n", b);
return 0;
}
int main14() {
short a = 10;
short b = 20;
printf("%hd\n", a);
printf("%hd\n", b);
return 0;
}
int main15() {
char a = "a";
char b = "9";
char c = "b";
printf("%d\n",a);
a = a + 1;
printf("%d\n",c);
printf("%d\n",b);
return 0;
}
int main16() {
char ch = 'A';
ch = ch + 1;
printf("%c\n",ch);
return 0;
}
int main17() {
char ch = 'a';
int length = sizeof(ch);
printf("%d\n", length);
printf("%d\n", sizeof('a'));//字符在内存中以二进制的形式存储
return 0;
}
int main18() {
char a = ' ';
a = a + ' ';
printf("%c\n", a);
return 0;
}
int main19() {
char a = 0;
char b = 0;
scanf("%c\n", &a);
scanf("%c\n", &b);
printf("%d\n", a);
printf("%d\n", b);
printf("%c\n", a+1);
printf("%c\n", b+2);
return 0;
}
int main20() {
int i = 0;
int sum = 0;
//求1+2+...+100的和
while (i<100)
{
i++;
sum = sum + i;
}
printf("%d\n", sum);
return 0;
}
int main21() {
int i = 0;
int sum = 0;
do
{
sum += i;
i++;
} while (i<=100);
printf("%d\n", sum);
return 0;
}
int main22() {
int i = 0;
int sum = 0;
for (; i<=100; i++)
{
sum += i;
}
printf("%d\n", sum);
return 0;
}
int main23() {
int a = 0;
int b = 0;
for (a=0;a<=2;a++ )
{
for (b=0;b<=3;b++)
{
for (int c=0;c<=4;c++)
{
printf("a=%db=%dc=%d\n", a, b, c);
}
}
}
return 0;
}
int main24() {
int a = 0;
int b = 0;
int c = 0;
while (a<=3)
{
while (b<=4)
{
c = 0;
while (c<=5)
{
printf("a=%db=%dc=%d\n", a, b, c);
c++;
}
}
a++;
b++;
}
return 0;
}
int main25() {
int oushu ;
int jishu;
int i = 0;
int k = 0;
for (int a=0;a<100;a++)
{
if (a % 2 != 0) {
oushu = a;
i++;
}
if (a % 2 == 0) {
jishu = a;
k++;
}
}
int size= sizeof(oushu) / sizeof(oushu);
int size1 = sizeof(jishu) / sizeof(jishu);
//printf("%d\n", size);
//printf("%d\n", size1);
for (i=0;i<sizeof(oushu)/sizeof(oushu);i++)
{
if (oushu<0)
{
break;
}
printf("%d", oushu);
printf("%s", ",");
}
printf("\n");
for (int j=0;j<sizeof(jishu)/sizeof(jishu);j++)
{
if (jishu<0)
{
break;
}
printf("%d", jishu);
printf("%s", ",");
}
printf("\n");
return 0;
}
int main26() {
goto hello;
printf("我会执行吗?");
hello: {
printf("hello");
return ok;
}
return 0;
}
int main27() {
int a = 0;
int b = 0;
char g;
printf("请输入第一个数:");
scanf("%d", &a);
printf("请输入第二个数:");
scanf("%d", &b);
printf("%s\n", a > b?("第一个数大于第二个数"):("第一个数小于第二个数"));
return ok;
}
int main28() {
char a[] = "hello";
char c = 0;
for (int b=0;b< pow(2, (sizeof(char) * 7)) - 1;b++)
{
c += 1;
printf("%c", c);
printf("\n");
}
printf("%s", a);
return ok;
}
int main29() {
char a[] = {'1','2','0'};//120烫烫泰辟?齓
char b[] = { 'a','g','f',0 };//agf
char c[] = { 'a','g','f',1 };//agf烫烫烫烫120烫烫泰辟?齓
char d[] = { 'g','t','a','\0' };//gta
char f[] = { 'g','r','s',"\0" };//grs
printf("%s\n", a);
printf("%s\n", b);
printf("%s\n", c);
printf("%s\n", d);
printf("%s\n", f);
return ok;
}
int main() {
char a = "";
char b="";
scanf("%c", &a);
scanf("%s", b);
printf("%c\n", a);
printf("%s\n", b);
printf("[%s]\n", b);
printf("%x\n", b);
return ok;
}
惭愧，曾经三度学习C，三度放弃C。实在没学会。 C语言只看过从入门到放弃的教程 谢谢分享 楼主的帖子不错，多发点~ 谢谢分享 感谢楼主 感谢楼主 感谢楼主 感谢楼主