[C]利用蔡勒公式简单实现万年历

测试代码

#include<stdio.h>

/**
  蔡勒公式
  0-星期日，1-星期一，2-星期二，3-星期三，4-星期四，5-星期五，6-星期六
**/

int getDayOfWeek(int year,int month,int day){
    if(month==1||month==2)//判断month是否为1或2　
    {
        year--;
        month+=12;
    }
    int c=year/100;
    int y=year-c*100;
    int week=(c/4)-2*c+(y+y/4)+(13*(month+1)/5)+day-1;
    while(week<0){week+=7;}
    week%=7;
    return week;
}

int main()
{
    int Days[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};      
    int year,month,day,days;
    while(scanf("%d%d",&year,&month)!=EOF)
    {

        days = Days[month];
        int weeks[6][7] = {0};
        int weekI = 0;
        for(int i=1;i<days+1;i++)
        {
            day = i;
            int week = getDayOfWeek(year,month,day);
            weeks[weekI][week] = i;
            if(week == 0)
                weekI++;
        }
        printf("星期一\t星期二\t星期三\t星期四\t星期五\t星期六\t星期日\n");
        for(int l=0;l<6;l++){
            for(int m=0;m<7;m++){
                if(weeks[l][(m+1)%7] > 0)
                    printf("%d\t",weeks[l][(m+1)%7]);
                else
                    printf("\t");
            }
            printf("\n");
        }
        printf("\n");
    }
    return 0;
}

效果展示：