明解C语言入门篇练习题第十章

练习10-1

#include<stdio.h>

void adjust_point(int *n)
{
	if (*n < 0)
		*n = 0;
	else
		if (*n > 100)
			*n = 100;
	return;
}

int main(void)
{
	int x;
	printf("input integer:");
	scanf("%d",&x);
	adjust_point(&x);
	printf("adjusted integer:%d\n",x);
	return 0;
}

练习10-2

#include<stdio.h>

void increment_date(int *y, int *m, int *d)
{
	if ((*m == 12) && (*d == 31))	//跨年
	{
		*y += 1;
		*m = 1;
		*d = 1;
	}
	else
		if (((*m == 1)&& (*d == 31)) ||  //跨月          
			((*m == 3) && (*d == 31))||
			((*m == 5) && (*d == 31))||
			((*m == 7) && (*d == 31))||
			((*m == 8) && (*d == 31))||
			((*m == 10) && (*d == 31))||
			((*m == 12) && (*d == 31))||
			((*m == 4) && (*d == 30))||
			((*m == 6) && (*d == 30))||
			((*m == 9) && (*d == 30))||
			((*m == 11) && (*d == 30))||
			(((*y)%4!=0)&&(*m==2)&&(*d==28))||                              //平年
			(((*y)%100==0)&&((*y)%400!=0)&& (*m == 2) && (*d == 28))||      //平年
			(((*y)%400==0)&&(*m==2)&&(*d==29))||                            //闰年
			((*y)%4==0)&&((*y)%100!=0)&&(*m==2)&&(*d==29))					//闰年
		{
			*m += 1;
			*d = 1;
		}
		else//不跨年不跨月
		{
			*d += 1;
		}
	return;
}

void decrement_date(int *y, int *m, int *d)
{
	if ((*m == 1) && (*d == 1))	//跨年
	{
		*y -= 1;
		*m = 12;
		*d = 31;
	}
	else
		if (((*m == 2) && (*d == 1)) ||  //跨月          
			((*m == 4) && (*d == 1)) ||
			((*m == 6) && (*d == 1)) ||
			((*m == 8) && (*d == 1)) ||
			((*m == 9) && (*d == 1)) ||
			((*m == 11) && (*d == 1)))
		{
			*m -= 1;
			*d = 31;
		}
		else
			if (((*m == 5) && (*d == 1)) ||   //跨月
				((*m == 7) && (*d == 1)) ||
				((*m == 10) && (*d == 1)) ||
				((*m == 12) && (*d == 1)))
			{
				*m -= 1;
				*d = 30;
			}
			else
				if ((((*y) % 4 != 0) && (*m == 3) && (*d == 1)) ||                              //跨月 平年 
					(((*y) % 100 == 0) && ((*y) % 400 != 0) && (*m == 3) && (*d == 1)))         //跨月 平年
				{
					*m -= 1;
					*d = 28;
				}
				else
					if ((((*y) % 400 == 0) && (*m == 3) && (*d == 1)) ||                            //跨月 闰年
						((*y) % 4 == 0) && ((*y) % 100 != 0) && (*m == 3) && (*d == 1))     		    //跨月 闰年
					{
						*m -= 1;
						*d = 29;
					}
					else //不跨年不跨月
					{
						*d -= 1;
					}
	return;
}

int main(void)
{
	int y, m, d;
	printf("input year month date:");
	scanf("%d %d %d",&y,&m,&d);
	decrement_date(&y, &m, &d);
	printf("decrement_date:%d %d %d\n",y,m,d);
	increment_date(&y, &m, &d);//抵消devrement_date
	increment_date(&y, &m, &d);
	printf("increment_date:%d %d %d\n",y,m,d);

	return 0;
}

练习10-3

#include<stdio.h>

void sort3(int *n1, int *n2, int *n3)
{
	int tmp;
	if (*n1 > *n2)
	{
		tmp = *n2;
		*n2 = *n1;
		*n1 = tmp;
	}
	if (*n1 > *n3)
	{
		tmp = *n3;
		*n3 = *n1;
		*n1 = tmp;
	}
	if (*n2 > *n3)
	{
		tmp = *n2;
		*n2 = *n3;
		*n3 = tmp;
	}
	return;
}

int main(void)
{
	int n1,n2,n3;
	printf("input n1 n2 n3:");
	scanf("%d %d %d",&n1,&n2,&n3);
	sort3(&n1,&n2,&n3);
	printf("sort:%d %d %d\n",n1,n2,n3);

	return 0;
}

练习10-4

#include<stdio.h>
#define NUM 5

void set_idx(int *v, int n)
{
	int i;
	for (i = 0; i < n; i++)
	{
		v[i] = i;
	}
	return;
}
int main(void)
{
	int i;
	int a[NUM];
	set_idx(a,NUM);
	for (i = 0; i < NUM; i++)
	{
		printf("a[%d] = %d\n",i,a[i]);
	}
	return 0;
}

练习10-5

#include <stdio.h>

void ary_set(int v[], int n, int val)
{
	int i;

	for (i = 0; i < n; i++)
		v[i] = val;
}

int main(void)
{
	int i;
	int a[] = { 1, 2, 3, 4, 5 };

	ary_set(&a[2], 5, 99);

	for (i = 0; i < 5; i++)
		printf("a[%d] = %d\n", i, a[i]);

	return 0;
}