12.txt

c primer 部分习题答案

#include <stdio.h>

void store(double ar[],int n);
void showall(double ar[],int a,int b);
double average(const double ar[],int n);
double averageall(const double ar[],int a,int b);
double max(const double ar[],int a,int b);

int main(void)
{
	double num[3][5];
	int i;

	for(i=0;i<3;i++)
	{
		printf("Please enter 5 numbers for row %d\n",i+1);
		store(num[i],5);
	}
	printf("you total enter:\n");
	showall(num,3,5);
	for(i=0;i<3;i++)
	{
		printf("The average number of row %d is %g\n",i+1,average(num[i],5));
	}
	printf("The average number of all is %g\n",averageall(num,3,5));
	return 0;
}
void store(double ar[],int n)
{
	int i;
	for(i=0;i<n;i++)
	{
		printf("Enter number %d",i+1);
		scanf("%lf",&ar[i]);
	}
}
void showall(double ar[],int a,int b)
{
	int i,j;
	for(i=0;i<a;i++)
	{
		for(j=0;j<b;j++)
		{
			printf("%g",ar[i][j]);
		}
	putchar('\n');
	}
}
double average(const double ar[],int n)
{
	int i,j;
	double sum = 0.0;
	for(i=0;i<n;i++)
		sum += ar[i];
	return sum / n;
}
double averageall(const double ar[],int a,int b)
{
	int i,j;
	double sum = 0.0;
	for(i=0;i<a;i++)
	{
		for(j=0;j<b;j++)
			sum += ar[i][j];
	}
	return sum / (a * b);
}
double max(const double ar[],int a,int b)
{
	int i,j;
	double max = ar[0][0];
	for(i=0;i<a;i++)
	{
		for(j=0;j<b;j++)
			if(max<ar[i][j])
				max = ar[i][j];
	}
	return max;
}