#include<stdio.h>
#define YEARS 5
#define MONTHs 12
int main(void)
{
     const float rain[YEARS][MONTHs]=
    {
        //初始化数组2000-20004年降水量
        {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;
    printf("Year   Rainfall(inches)\n");
    for(year=0,total=0;year<YEARS;year++)
    {
        for(month=0,subtot=0;month<MONTHs;month++)
            subtot+=*(*(rain+year)+month);      //这一行怎么理解？
        printf("%5d%5.1f\n",2000+year,subtot);
        total+=subtot;  
    }
    printf("The yearly average is %.1f\n",total/YEARS);
    printf("MONTHLY AVERAGEE:\n\n");
    printf("Jan\tFeb\tMar\tApr\tMay\tJun\tJul\tAug\tSep\tOct\tNov\tDec\n");
    for(month=0;month<MONTHs;month++)
    {
        for(year=0,subtot=0;year<YEARS;year++)
            subtot+=*(*(rain+year)+month);
        printf("%.1f\t",subtot/YEARS);
    }
    printf("\n");
    return 0;
   
}

subtot+=*(*(rain+year)+month);      //这一行怎么理解？
subtot += rain[year][month];

大哥，这代码是你自己写的吗？