计算机程序设计C++ MOOC
测试与作业C++基础练习100题
##第三周基本练习
- 判断奇偶数
#include "iostream"
using namespace std;
int main()
{
int a;
cin >> a;
if (a % 2 == 0)
{
cout << "even" << endl;
}
else
{
cout << "odd" << endl;
}
return 0;
}
- 判断数的类型
#include "iostream"
using namespace std;
int main()
{
double a;
cin >> a;
if (a>0&&int(a)!=a)
{
cout << "positive real" << endl;
}
else if (a>0&&int(a)==a)
{
cout << "positive integer" << endl;
}
else if (a<0 && int(a) != a)
{
cout << "negative real" << endl;
}
else if (a<0 && int(a) == a)
{
cout << "negative integer" << endl;
}
else if (a == 0)
{
cout << "zero" << endl;
}
return 0;
}
- 判断点的象限
#include "iostream"
using namespace std;
int main()
{
double a, b;
cin >> a >> b;
if (a > 0 && b > 0)
{
cout << "1" << endl;
}
else if (a > 0 && b < 0)
{
cout << "4" << endl;
}
else if (a < 0 && b>0)
{
cout << "2" << endl;
}
else if (a < 0 && b < 0)
{
cout << "3" << endl;
}
return 0;
}
- 判断字符类型
#include "iostream"
using namespace std;
int main()
{
char a;
cin >> a;
if (a >= '0'&&a <= '9')
{
cout << "0" << endl;
}
else if (a >= 'A'&&a <= 'Z')
{
cout << "1" << endl;
}
else if (a >= 'a'&&a <= 'z')
{
cout << "2" << endl;
}
else
{
cout << "-1" << endl;
}
return 0;
}
- 百分制成绩转五分制成绩
#include "iostream"
using namespace std;
int main()
{
int grade;
cin >> grade;
switch (grade / 10)
{
case 10:
cout << "5" << endl;
break;
case 9:
cout << "5" << endl;
break;
case 8:
cout << "4" << endl;
break;
case 7:
cout << "3" << endl;
break;
case 6:
cout << "2" << endl;
break;
case 0:
cout << "0" << endl;
break;
default:
cout << "1" << endl;
}
return 0;
}
- 显示n个字符
#include "iostream"
using namespace std;
int main()
{
int number,i;
char a;
cin >> number >> a;
for (i = 0; i < number; i++)
{
cout << a;
}
cout << endl;
return 0;
}
- 显示字符组成的矩形
#include "iostream"
using namespace std;
int main()
{
int number1,number2,i,j;
char a;
cin >> number1>>number2 >> a;
for (i = 0; i < number1; i++)
{
for (j = 0; j < number2; j++)
{
cout << a;
}
cout << endl;
}
return 0;
}
- 用循环计算1+2+3+…+n
#include "iostream"
using namespace std;
int main()
{
int n, sum=0,i;
cin >> n;
i = 1;
while (i <= n)
{
sum = sum + i;
i++;
}
cout << sum << endl;
return 0;
}
- 计算1+1/2+1/3+…+1/n
#include "iostream"
using namespace std;
int main()
{
int n, i;
double sum = 0;
cin >> n;
if (n != 0)
{
for (i = 1; i <= n; i++)
{
sum = sum + 1.0 / i;
}
}
cout << sum << endl;
return 0;
}
- 计算n！
#include "iostream"
using namespace std;
int main()
{
int n, mul=1,i;
cin >> n;
if (n != 0)
{
for (i = 1; i <= n; i++)
{
mul = mul*i;
}
}
cout << mul << endl;
return 0;
}
- 交替输出1和-1
#include "iostream"
using namespace std;
int main()
{
int n,i,a=1;
cin >> n;
cout << a;
for (i = 2; i <= n; i++)
{
a = a*-1;
cout << " " << a;
}
return 0;
}
- 判断整数的位数
#include "iostream"
using namespace std;
int main()
{
int a, n = 1;
cin >> a;
a = a / 10;
while (a)
{
a = a / 10;
n++;
}
cout << n << endl;
return 0;
}
- 求非负整数的各位数字的和
#include "iostream"
using namespace std;
int main()
{
int a,sum=0;
cin >> a;
while (a)
{
sum = sum + a % 10;
a = a / 10;
}
cout << sum << endl;
return 0;
}
- 九九乘法表
#include "iostream"
using namespace std;
int main()
{
int n,i,j;
cin >> n;
for (i = 1; i <= n; i++)
{
for (j = 1; j < i; j++)
{
cout << i << "*" << j << "=" << i*j << " ";
}
cout << i << "*" << j << "=" << i*j ;
cout << endl;
}
return 0;
}
- 不一样的九九乘法表
#include "iostream"
using namespace std;
int main()
{
int n, i, j;
cin >> n;
for (i = n; i >= 1; i--)
{
for (j = 1; j < i; j++)
{
cout << i << "*" << j << "=" << i*j << " ";
}
cout << i << "*" << j << "=" << i*j;
cout << endl;
}
return 0;
}
- Fibonacci序列
#include "iostream"
using namespace std;
int main()
{
int n, fib=1,fib_1=1,fib_2=0;
cin >> n;
cout << "0";
while (n)
{
cout <<" "<<fib;
fib = fib_1 + fib_2;
fib_2 = fib_1;
fib_1 = fib;
n--;
}
return 0;
}
以上为第三次基础练习。