[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：