#include<stdio.h>
int main()
{

    int firstday(int year);

    int sw,leap,i,j,k,wd,day;  
   
    int date[12][6][7];         //定义一个三维数组 分别对应 月、周、日
    char title[] = "SUN MON TUE WED THU FRI SAT";
    int day_tab[][12] = {
                        {31,28,31,30,31,30,31,31,30,31,30,31},
                        {31,29,31,30,31,30,31,31,30,31,30,31}
                        };        //平年和闰年的月份天数
    int year;


    printf("please input the year:");
    scanf("%d",&year);         

    sw = firstday(year);        //计算这一年的第一天是星期几
    leap = (year%4 ==0 && year%100 != 0) || year%400 ==0;
    for( i=0; i<12; i++ )
        for( j=0; j<6; j++)
            for( k=0; k<7; k++)
                date[i][j][k] = 0;   //将所有的日期都归零
    for( i=0; i<12; i++)
        for( wd=0,day=1; day<=day_tab[leap][i]; day++)
        {
            date[i][wd][sw] = day;
            sw = ++sw%7;
            if(sw == 0)
                wd++;
        }

printf("\n==================The Calendar of Year %d=======================\n ",year);
for( i=0; i<6; i++)
{
    for(wd=0,k=0;k<7;k++)                   //将同一行的天数相加
        wd = wd + date[i][5][k] + date[i+6][5][k];
    wd=wd>0? 6:5;
    printf("%2d  %s  %2d  %s   \n",i+1,title,i+7,title);

    for(j=0;j<wd;j++)
    {
        printf("   ");
        for( k=0; k<7; k++)
            if(date[i][j][k])
                printf("%4d",date[i][j][k]);
            else printf("   ");
            printf("      ");
        for( k=0; k<7; k++)
            if(date[i+6][j][k])
                printf("%4d",date[i+6][j][k]);
            else printf("   ");
            printf(" \n");
    }
}

    puts("==================================================================");
    return 0;
}


/*计算该年份第一天是星期几*/
int firstday(int year)
{
    int leap(int ye);

    int i;
    long int n;

   
    n = year*365;

    for(i = 1; i < year; i++)
        if(leap(i))
            n += 1;   
    return (n%7);
}

int leap(int ye)
{
    if( (ye%4 ==0 && ye%100 != 0) || ye%400 ==0 )
        return 1;
    else
    return 0;
}


程序结果字符总是不对齐  哪边出错了呢

这下对了，真厉害！

不错，复制回去研究下