练习5&&习题5

练习5-1

#include <stdio.h>

int sum(int m, int n);

int main()
{    
    int m, n;

    scanf("%d %d", &m, &n);
    printf("sum = %d\n", sum(m, n));
    
    return 0;
}

/* 你的代码将被嵌在这里 */
int sum(int m,int n)
{
    int i;
    int sum = 0;
    
    for (i = m;i <= n;i++)
    {
        sum += i;
    }

    return sum;
}

/*               20230427               */

练习5-2

#include <stdio.h>

int max( int a, int b );

int main()
{    
    int a, b;

    scanf("%d %d", &a, &b);
    printf("max = %d\n", max(a, b));
    
    return 0;
}

/* 你的代码将被嵌在这里 */
int max(int a,int b)
{
    if (a >= b)
        return a;
    else
        return b;
}

练习5-3

注：因为一个字符占两个位置，所以要减两次，要处理两点，第一是需要打印几个空格，第二是需要打印几个字符，要这样进行分析

#include <stdio.h>

void CharPyramid( int n, char ch );

int main()
{    
    int n;
    char ch;

    scanf("%d %c", &n, &ch);
    CharPyramid(n, ch);
    
    return 0;
}

/* 请在这里填写答案 */
void CharPyramid(int n,char ch)
{
	int i,j,k,m; 
    for (m = n,i = 1;i <= n;i++,m--)
    {
        for (j = m;j > 0;j--)
        {
             if (j != 1)
             printf(" ");
        }
        for (k = i;k > 0;k--)
        {
            printf("%c ",ch);
        }

        printf("\n");
    }
}

习题5-1

#include <stdio.h>

int sign( int x );

int main()
{
    int x;

    scanf("%d", &x);
    printf("sign(%d) = %d\n", x, sign(x));
    
    return 0;
}

/* 你的代码将被嵌在这里 */
int sign(int x)
{
    if (x > 0)
    {
        return 1;
    }
    else if (x == 0)
    {
        return 0;
    }
    else
    {
        return -1;
    }
}

习题5-2

#include <stdio.h>

#define MAXN 10

int even( int n );
int OddSum( int List[], int N );

int main()
{    
    int List[MAXN], N, i;

    scanf("%d", &N);
    for ( i=0; i<N; i++ ) {
        scanf("%d", &List[i]);
    }
    printf("Sum of ( ");
    for ( i=0; i<N; i++ ) {
        if ( even(List[i])==0 )
            printf("%d ", List[i]);
    }
    printf(") = %d\n", OddSum(List, N));
    
    return 0;
}

/* 你的代码将被嵌在这里 */
int even(int n)
{
    if (n % 2 == 0)
    {
        return 1;
    }
    else
    {
        return 0;
    }
}

int OddSum(int List[],int N)
{
    int i,sum;
    
    sum = 0;
    
    for (i = 0;i < N;i++)
    {
    	if  ( even(List[i]) == 0 )
       	 	sum += List[i];
    }

    return sum;
}

习题5-2

#include <stdio.h>
#include <math.h>

double dist( double x1, double y1, double x2, double y2 );

int main()
{    
    double x1, y1, x2, y2;

    scanf("%lf %lf %lf %lf", &x1, &y1, &x2, &y2);
    printf("dist = %.2f\n", dist(x1, y1, x2, y2));
    
    return 0;
}

/* 你的代码将被嵌在这里 */
double dist(double x1,double y1,double x2,double y2)
{
    double sum;

    sum = sqrt((x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1));

    return sum;
}

/*               20230428               */