【明解C语言】第四章--代码清单和练习
作者：互联网
代码清单4-1--判断奇偶数
int main()
{
int cont;
do
{
int no;
printf("请输入一个整数：");
scanf("%d", &no);
if (no % 2)
{
printf("这是奇数");
}
else {
printf("这是偶数");
}
printf("要重复一次吗");
scanf("%d", &cont);
} while (cont == 0);
return 0;
}
代码清单4-3
int main()
{
int num;
int dig;
do {
printf("请输入一个非负整数:");
scanf("%d", &num);
if (num < 0)
{
puts("\a请不要输入负数");
}
} while (num < 0);
dig = 0;
do {
num /= 10;//每次退掉末尾数
dig += 1;//每次进入do，计数加1
} while (num > 0);
printf("该整数的位数%d\n", dig);
return 0;
}
//代码清单4-4--求和
int main()
{
int no = 1;
int sum = 0;
do {
sum += no;//1 1+2 1+2+3 1+2+3+4 1+2+3+4+5
no += 1; //2 3 4 5 6跳出循环
} while (no <= 5);
printf("1到5的合计值是%d\n", sum);
return 0;
}
//练习4-1--逆向输出+计数
int main()
{
int no = 0;
int i = 0;
printf("请输入一个非负整数：");
scanf("%d", &no);
do
{
printf("%d\n", no % 10);
no /= 10;
i+=1;
} while (no>0);
printf("该数的位数是i=%d\n", i);
return 0;
}
//练习4-3
int main()
{
int num1, num2, sum;
puts("请输入两整数");
scanf("%d %d", &num1, &num2);
int i;
for (i = num1,sum=0; i <= num2; i++)
{
sum += i;
}
printf("%d到%d之间的所有整数和是%d", num1,num2,sum);
return 0;
}
int main()
{
int n1, n2;
int sum = 0;
puts("请输入两个数：");
scanf("%d %d", &n1, &n2);
int i = n1;
do
{
sum += i;
i++;
} while (i <= n2);
printf("%d到%d的合计值是%d", n1, n2, sum);
return 0;
}
//代码清单4-5
int main()
{
int no = 1;
int sum = 0;
do
{
sum += no;
no += 1;
} while (no <= 5);
printf("1到5的合计值是%d", sum);
return 0;
}
//代码清单4-6--n+=1和n++
int main()
{
int no = 1;
int sum = 0;
do
{
sum += no;
no++;
} while (no <= 5);
printf("1dao5的合计值是%d", sum);
return 0;
}
//练习4-4--使用/= 替换n=n/10
//练习4-5 使用/=和++替换n=n/10，n+=1
int main()
{
int num;
do
{
printf("请输入一个非负整数：");
scanf("%d", &num);
if (num < 0)
puts("请不要输入负数");
} while (num < 0);
printf("该整数的逆向显示结果是：");
do
{
printf("%d", num % 10);//取出末尾数字
num /= 10;//重新赋值
} while (num > 0);
puts("。");
return 0;
}
int main()
{
int num;
int dig;
do
{
printf("请输入一个非负整数：");
scanf("%d", &num);
if (num < 0)
puts("\a请不要输入负数。");
} while (num < 0);
dig = 0;
do
{
num /= 10;//每次舍弃末尾数字
dig += 1;//计数器加1
} while (num > 0);
printf("该整数的位数是%d",dig);
return 0;
}
--------------------------------------------------------
while循环
// while循环
//代码清单4-7
int main()
{
int no;
printf("请输入一个整数：");
scanf("%d", &no);
while (no >= 0)
{
printf("%d", no);
no--;
}
putchar("\n");//回显字符串
return 0;
}
//练习4-6
int main()
{
int no;
printf("请输入一个正数：");
scanf("%d", &no);
while (no >= 0)
{
printf("%d", no--);
}
putchar("\n");
return 0;
}
//代码清单4-9
int main()
{
int i, no;
printf("请输入一个正数：");
scanf("%d", &no);
i = 0;
while (i <= no) {
printf("%d", i++);
}
putchar('\n');
return 0;
}
//代码清单4-11
int main()
{
int i = 0;
int sum = 0;
int num,tmp;
printf("要输入多少个整数:");
scanf("%d", &num);//3
while (i < num)//i<3 0 1 2 3-退出
{
printf("NO.%d",++i); //1 2 3
scanf("%d", &tmp); //4 5 6
sum += tmp; //4 9 15
}
printf("合计值：%d\n", sum);//15
printf("平均值：%.2f\n", (double)sum / num);//5
return 0;
}
---------------------------------------------------
4-3for语句
//代码清单4-12--简单的遍历
int main()
{
int i, no;
printf("请输入一个正数：");
scanf("%d", &no);
for (i = 0; i <= no; i++)
{
printf("%d", i);
}
putchar('\n');
return 0;
}
//代码清单4-13--for循环输出字符串
int main()
{
int i, no;
printf("请输入一个正数：");
scanf("%d",&no);
for (i = 1; i <= no; i++)
putchar('*');
putchar('\n');
return 0;
}
//代码清单4-14
int main()
{
int i;
int sum = 0;
int num, tmp;
printf("输入多少个整数：");
scanf("%d", &num);//3
for (i = 0; i < num; i++)//0 1 2 3-退出
{
printf("No.%d", i + 1);//1 2 3
scanf("%d", &tmp); //1 3 5
sum += tmp; //1 4 9
}
printf("合计值：%d\n", sum);//9
printf("平均值：%.2f\n", (double)sum / num);//3.00
return 0;
}
//练习4-12--对代码清单4-6修改，计算1~5的和
int main()
{
int no = 0;
int sum = 0;
for (no = 1; no <= 5; no++)
sum += no;
printf("1~5的合计值是:%d",sum);
return 0;
}
标签：no,--,明解,C语言,int,while,num,printf,main 来源： https://www.cnblogs.com/sdr900/p/16483118.html