[C++知识库]大一期末复习—C语言程序专题

大一上期末复习——编程

九九加法表

#include<stdio.h>//循环嵌套
int main()
{
	int i, j;
	for (i = 1; i <= 9; i++)
	{
		for (j = 1; j <= i; j++)
		{
			printf("%d+%d=%2d", i, j, i + j);
		}
		printf("\n");
	}
	return 0;
}

排序

#include<stdlib.h>
#include<stdio.h>
#include<string.h>
void printA1(int a[], int length);//遍历数组
void sortA1(int a[], int length)//定义函数，引用函数
{
	int i, j, temp;
	for (i = 0; i < length; ++i)
	{
		for (j = i + 1; j < length; ++j)
		{
			if (a[j] < a[i])//如果后一个元素小于前一个元素，则交换
			{
				temp = a[i];
				a[i] = a[j];
				a[j] = temp;
			}
		}
	}
}
void printA1(int a[], int length)
{
	int i;
	for (i = 0; i < length; ++i)
	{
		printf("%d,", a[i]);
	}
	printf("\n");
}
void main()
{
	int length = 0;
	int a[] = { 12,43,8,50,100,52,0 };
	length = sizeof(a) / sizeof(a[0]);
	printf("排序前\n");
	printA1(a, length);
	sortA1(a, length);
	printf("选择排序后\n");
	printA1(a, length);
	system("pause");
}

水仙花数

#include<stdio.h>
void main()
{
	int n = 100, i, j, k;
	do {
		i = n / 100;//百位
		j = (n / 10) % 10;//十位
		k = n % 10;//个位
		if (n == i * i * i + j * j * j + k * k * k)//该三位数的每位数的立方和等于该数本身
			printf("%d是水仙花数\n", n);
		n = n + 1;//可去
	} while (n <= 999);//n的范围
}

最大公约数最小公倍数

#include<stdio.h>
int main()
{
	int m, n, a, b, t, c;
	printf("Input two integer numbers:\n");
		scanf_s("%d%d", &a, &b);
		m = a; n = b;
		while (b != 0)//若余数不为0，继续相除，直到余数为0
		{
			c = a % b; a = b; b = c;
		}
		printf("The largest common divisor:%d\n", a);
		printf("The least common multiple:%d\n", m * n / a);
}

静态局部变量实例

#include<stdio.h>
int fun(int n);//求n！
int main()
{
	int i;
	for (i = 1; i <= 5; i++)
		printf("%d!=%d\n", i, fun(i));
	return 0;
}//采用静态局部变量求阶乘
int fun(int n)
{
	static int f = 1;//定义静态局部变量f
	f = f * n;//f保存了（n-1）！的结果，本语句得到n！
	return f;
}

判断素数

#include<stdio.h>
#include<math.h>
int count;
int judgePrime(int n);
int main()
{
	int i;
	printf("The primes between 2 to 100:\n");
	for(i=2;i<100;i++)
		if (judgePrime(i))
		{
			printf("%d", i);
			count++;
		}
	printf("The total number of primes: %d\n", count);
	return 0;
}
int judgePrime(int n)
{
	int i;
	int judge = 1;
	if (n == 1)
		judge = 0;
	{
		int k = (int)sqrt(n);
		for (i = 2; judge && i <= k; i++)
			if (n % i == 0)
				judge = 0;
	}
	return judge;
}

指针测试

#include<stdio.h>
void s(int* a, int b)
{
	int t = *a; *a = b; b = t;
}
int main()
{
	int x = 1, y = 8;
	s(&x, y);
	printf("%d,%d\n", x, y);
	return 0;
}

循环测试——输出素数

#include<stdio.h>
void main()
{
	int n, i;
	for (n = 3; n <= 100; n = n + 1)
	{
		for (i = 2; i <= n - 1; i = i + 1)
			if (n % i == 0)break;
		if (i >= n)printf("%d\t", n);
	}
}

循环测试——左下角

#include<stdio.h>
void main()
{
	int m, n;
	for (n = 1; n <= 9; n = n + 1)
	{
		for (m = 1; m <= n; m = m + 1)
			printf("%4d", m);
		printf("\n");
	}
}

阶乘算和

#include<stdio.h>
void main()
{
	int n, s = 0, t = 1;
	for (n = 1; n <= 10; n++)
	{
		t = t * n;
		s = s + t;
	}
	printf("1+2!+3!...+10!=%d\n", s);
}