C PRIMER PLUS（第六版编程练习）10.13编程练习_1题

/*修改程序清单10.7的rain.c程序，用指针进行计算（仍然要声明并初始化数组）。

*/
#include<stdio.h>
#define MONTHS 12
#define YEARS 5
int main(void)
{
	const float rain[YEARS][MONTHS] =
	{
		{4.3,4.3,4.3,3.0,2.0,1.2,0.2,0.2,0.4,2.4,3.5,6.6},
		{8.5,8.2,1.2,1.6,2.4,0.0,5.2,0.9,0.3,0.9,1.4,7.3},
		{9.1,8.5,6.7,4.3,2.1,0.8,0.2,0.2,1.1,2.3,6.1,8.4},
		{7.2,9.9,8.4,3.3,1.2,0.8,0.4,0.0,0.6,1.7,4.3,6.2},
		{7.6,5.6,3.8,2.8,3.8,0.2,0.0,0.0,0.0,1.3,2.6,5.2}
	};
	int year, month;
	float subtot, total;
	float * p1;
	p1 = rain;

	printf("YEAR    RAINFALL (inches)\n");
	for (year = 0, total = 0; year < YEARS; year++)
	{
		for (month = 0, subtot = 0; month < MONTHS; month++)
		{
			subtot += *p1;
			p1++;
		}
		printf("%5d %15.1f\n", 2010 + year, subtot);
		total += subtot;
	}
	printf("\nThe yearly average is %.1f inches.\n\n", total / YEARS);
	printf("MONTHLY AVERAGES:\n\n");
	printf("Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec\n");
	;
	p1 = rain;
	//p1 = rain;
	//printf("*p1=%f", *p1);

	for (month = 0; month < MONTHS; month++)
	{
		for (year = 0, subtot = 0; year < YEARS; year++)
		{
			//subtot += *(*(rain + year) + month);
			subtot += *p1;
			p1 += MONTHS;
		}
		
		printf("%4.1f\t", subtot/YEARS);
		p1 = rain;
		p1 += month+1;
	}
	return 0;
}