C语言封装函数算法整理

1. 输入两个数，找出两个数的最大公约数和最小公倍数——

#include <stdio.h>
 
int GetComDivNum(int x, int y)
{
	int i = 0;
	int min = 0;
 
	min = x < y ? x : y;
	for (i = min; i >= 1; i--)
	{
		if (0 == x % i && 0 == y % i)	
		{
			break;
		}
	}
 
	return i;
}
 
int GetComMulNum(int x, int y)
{
	int i = 0;
	int max = 0;
 
	max = x > y ? x : y;
	for (i = max; i <= x * y; i++)
	{
		if (0 == i % x && 0 == i % y)
		{
			break;
		}
	}
 
	return i;
}
 
int main(void)
{
	int num1 = 0;
	int num2 = 0;
	int divnum = 0;
	int mulnum = 0;
 
	scanf("%d%d", &num1, &num2);
 
	divnum = GetComDivNum(num1, num2);
	mulnum = GetComMulNum(num1, num2);
 
	printf("最大公约数:%d\n", divnum);
	printf("最小公倍数:%d\n", mulnum);
	
	return 0;
}
 

2. 输入年、月、日，获得该年剩余多少天——

#include <stdio.h>
 
int IsLeepYear(int tmpyear)
{
	if ((0 == tmpyear % 4 && tmpyear % 100 != 0) || (0 == tmpyear % 400))
	{
		return 1;
	}
 
	return 0;
}
 
int GetDayOfYear(int tmpyear, int tmpmon, int tmpday)
{
	int i = 0;
	int sum = 0;
  	int a1[12] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
   	int a2[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
    
    if (IsLeepYear(tmpyear))
    {
        for (i = 0; i < tmpmon-1; i++)
        {
            sum += a1[i];
        }
    }else
    {
        for (i = 0; i < tmpmon-1; i++)
        {
            sum += a2[i];
        }
    }
	sum += tmpday;
 
	return sum;
}
 
int GetLeftDayOfYear(int tmpyear, int tmpmon, int tmpday)
{
	int sum = 0;
	
	if (IsLeepYear(tmpyear))
	{
		sum = 366;
	}
	else 
	{
		sum = 365;
	}
	
	return sum - GetDayOfYear(tmpyear, tmpmon, tmpday);
}
 
int main(void)
{
	int year = 0;
	int mon = 0;
	int day = 0;
	int leftday = 0;
 
	scanf("%d%d%d", &year, &mon, &day);
 
	leftday = GetLeftDayOfYear(year, mon, day);
	printf("%d年剩余%d天\n", year, leftday);
 
	return 0;
}
 

3. 封装函数，以数组传递形式实现strlen、strcpy、strcat、strcmp——

#include <stdio.h>
 
int Mystrlen(char pstr[])
{
	int i = 0;
	int cnt = 0;
 
	while (pstr[i] != '\0')
	{
		cnt++;
		i++;
	}
 
	return cnt;
}
 
int Mystrcpy(char pdst[], char psrc[])
{
	int i = 0;
 
	while (psrc[i] != '\0')
	{
		pdst[i] = psrc[i];
		i++;
	}
	pdst[i] = '\0';
 
	return 0;
}
 
int Mystrcat(char pstr1[], char pstr2[])
{
	int i = 0;
	int j = 0;
 
	while (pstr1[i] != '\0')
	{
		i++;
	}
 
	while (pstr2[j] != '\0')
	{
		pstr1[i] = pstr2[j];
		i++;
		j++;
	}
	pstr1[i] = '\0';
 
	return 0;
}
 
int Mystrcmp(char pstr1[], char pstr2[])
{
	int i = 0;
 
	while (pstr1[i] == pstr2[i] && pstr1[i] != '\0')
	{
		i++;
	}
 
	return pstr1[i] - pstr2[i];
}
 
int main(void)
{
	char str[32] = {0};
	char dst[32] = {0};
	int len = 0;
	int ret = 0;
 
	gets(str);
 
	len = Mystrlen(str);
	printf("len = %d\n", len);
 
	Mystrcpy(dst, str);
	printf("dst = %s\n", dst);
	
	Mystrcat(dst, str);
	printf("dst = %s\n", dst);
 
	ret = Mystrcmp(dst, str);
	printf("ret = %d\n", ret);
 
	return 0;
}
 

4. 封装函数，以指针传递形式实现strlen、strcpy、strcat、strcmp

4.1 strlen

#include <stdio.h>
 
int MyStrlen(char *pstr)
{
	int cnt = 0;
 
	while (*pstr != '\0')
	{
		cnt++;
		pstr++;
	}
 
	return cnt;
}
 
int main(void)
{
	char str[32] = {0};
	int len = 0;
 
	gets(str);
 
	len = MyStrlen(str);
	printf("len = %d\n", len);
 
	return 0;
}
 

4.2 strcpy

#include <stdio.h>
#include <string.h>
 
int MyStrcpy(char *pdst, char *psrc)
{
	while (*psrc != '\0')
	{
		*pdst = *psrc;
		psrc++;
		pdst++;
	}
 
	*pdst = '\0';
 
	return 0;
}
 
int main(void)
{
	char src[32] = {0};
	char dst[32] = {0};
 
	gets(src);
 
	MyStrcpy(dst, src);
	
	printf("dst = %s\n", dst);
 
	return 0;
}
 

4.3 strcat

#include <stdio.h>
#include <string.h>
 
int MyStrcat(char *pstr1, char *pstr2)
{
	while (*pstr1 != '\0')
	{
		pstr1++;
	}
 
	while (*pstr2 != '\0')
	{
		*pstr1 = *pstr2;
		pstr1++;
		pstr2++;
	}
	*pstr1 = '\0';
 
	return 0;
}
 
int main(void)
{
	char str1[32] = {0};
	char str2[32] = {0};
 
	gets(str1);
	gets(str2);
 
	MyStrcat(str1, str2);
	
	printf("str1 = %s, str2 = %s\n", str1, str2);
 
	return 0;
}
 

4.4 strcmp

#include <stdio.h>
 
int MyStrcmp(char *pstr1, char *pstr2)
{
	while (*pstr1 == *pstr2 && *pstr1 != '\0')
	{
		pstr1++;
		pstr2++;
	}
 
	return *pstr1 - *pstr2;
}
 
int main(void)
{
	char str1[32] = {0};
	char str2[32] = {0};
	int ret = 0;
 
	gets(str1);
	gets(str2);
 
	ret = MyStrcmp(str1, str2);
 
	printf("ret = %d\n", ret);
 
	return 0;
}
 

5. 判断素数——

#include <stdio.h>
 
int IsPrimayNum(int n)
{
	int i = 0;
 
	for (i = 2; i < n; i++)
	{
		if (0 == n % i)
		{
			return 0;
		}
	}
	
	return 1;
}
 
int main(void)
{
	int num = 0;
 
	scanf("%d", &num);
 
	if (IsPrimayNum(num))
	{
		printf("Yes!\n");
	}
	else 
	{
		printf("No!\n");
	}
 
	return 0;
}
 

6. 封装函数实现斐波那切数列    1 1 2 3 5 8 13 21 34 55 ——

#include <stdio.h>
 
int Fibo(int num)
{
    if (1 == num || 2 == num)
    {
        return 1;
    }else
    {
        return Fibo(num-1) + Fibo(num-2);
    }
}
 
int main(void)
{
    int num = 0;
    int fibo = 0;
 
    scanf("%d", &num);
 
    fibo = Fibo(num);
 
    printf("fibo = %d\n", fibo);
 
    return 0;
}

7. 递归实现汉诺塔——

#include <stdio.h>
 
int HanNuoTa(int n, char src, char tmp, char dst)
{
	if (1 == n)
	{
		printf("%c -> %c\n", src, dst);
	}
	else 
	{
		HanNuoTa(n-1, src, dst, tmp);
		HanNuoTa(1, src, tmp, dst);
		HanNuoTa(n-1, tmp, src, dst);
	}
 
	return 0;
}
 
int main(void)
{
	int n = 0;
 
	scanf("%d", &n);
 
	HanNuoTa(n, 'A', 'B', 'C');
 
	return 0;
}
 

8. 拆分数字各个位数，并将各个位数求和（除10（/10），再对10求余(%10)）——

#include <stdio.h>
 
int fun(int tmp)
{
	int sum = 0;
 
	while (tmp != 0)
	{
		sum += tmp % 10;
		tmp /= 10;
	}
 
	return sum;
}
 
int main(void)
{
	int num = 0;
	int sum = 0;
 
	scanf("%d", &num);
 
	sum = fun(num);
 
	printf("sum = %d\n", sum);
 
	return 0;
}
 

9. 封装一个函数传入数组和n,根据n的值将数组完成转换——
    int a[5] = {1, 2, 3, 4, 5}
        n=3                        n=2
    3 4 5 1 2                4 5 1 2 3 

#include <stdio.h>
 
int OutputArray(int arrayp[], int tmplen)
{
    int i = 0;
 
    for (i = 0; i < tmplen; i++)
    {
        printf("%d ", arrayp[i]);
    }
    putchar('\n');
 
    return 0;
}
 
int Fun(int arrayp[], int len, int n)
{
    int i = 0;
    int j = 0;
    int tmp = 0;
 
    for (i = 0; i < n; i++)
    {
        tmp = arrayp[len-1];
        for (j = len-1; j > 0; j--)
        {
            arrayp[j] = arrayp[j-1];
        }
        arrayp[0] = tmp;
    }
}
 
int main(void)
{
    int str[5] = {1, 2, 3, 4, 5};
    int len = 5;
    int n = 0;
    
    scanf("%d", &n);
 
    OutputArray(str, len);
    Fun(str, len, n);
    OutputArray(str, len);
 
    return 0;
}