《c primer plus》编程练习回顾-第九章

1.

#include<stdio.h>double min(double a, double b);int main(void){    double x, y;    scanf("%lf%lf", &x, &y);    printf("%lf", min(x, y));    return 0;}double min(double a, double b){    return a < b ? a : b;}

2.

#include<stdio.h>void chline(char ch, int i, int j);int main(void){    char ch;    int a, b;    scanf("%c%d%d", &ch, &a, &b);    chline(ch, a, b);    return 0;}void chline(char ch, int i, int j){    for (int k = 1; k < i; k++)        printf(" ");    for (; i <= j; i++)        printf("%c", ch);}

3

#include<stdio.h>void fun(char ch, int a, int b);int main(void){    char ch;    int x, y;    scanf("%c%d%d", &ch, &x, &y);    fun(ch, x, y);    return 0;}void fun(char ch, int a, int b){    for (int i = 0; i < a; i++)    {        for (int i = 0; i < b; i++)            printf("%c", ch);        printf("\n");    }}

4.

#include<stdio.h>double fun(double a, double b);int main(void){    double x, y;    scanf("%lf%lf", &x, &y);    printf("%lf", fun(x, y));    return 0;}double fun(double a, double b){    double c;    c = 1 / ((1 / a + 1 / b) / 2);    return c;}

5.

#include<stdio.h>void larger_of(double *a, double *b);int main(void){    double x, y;    scanf("%lf%lf", &x, &y);    larger_of(&x, &y);    printf("%lf %lf\n", x, y);    return 0;}void larger_of(double *a, double *b){    *a = *b = *a > *b ? *a : *b;}

6.

#include<stdio.h>#include<ctype.h>int fun(char ch);int main(void){    char ch;    scanf("%c", &ch);    printf("%c\'s position is %d\n", ch, fun(ch));    return 0;}int fun(char ch){    int a;    char ch1;    if (isalpha(ch))    {        printf("%c is a alpha.\n", ch);        ch1 = toupper(ch);        a = ch1 - 65 + 1;        return a;    }    else        return -1;}

7.

#include<stdio.h>#include<math.h>double power(double x, int y);int main(void){    double a;    int b;    while (scanf("%lf%d", &a, &b) == 2)    {        printf("%lf\n", power(a, b));    }    return 0;}double power(double x, int y){    double c = 1;    if (y > 0)    {        for (int i = 0; i < y; i++)            c *= x;        return c;    }    else if (y < 0)    {        for (int i = 0; i < -y; i++)            c /= x;        return c;    }    else if (x != 0)        return 1;    else        return 1 / x;}

8.

*

9.

这里写代码片