c语言：万年历

用蔡勒公式计算星期
可以查询具体月份

#include
#include
void year_cd();//年历函数
void month_cd(int months);//月历函数
int year,month,day=1,week,i,j,k;
int years[12][6][7]= {0};//年历数组
int monthname[12]= {31,28,31,30,31,30,31,31,30,31,30,31};
char weekname[]="SUN  MON  TUE  WED  THU  FRI  SAT";
int main() {
    char flage;
    scanf("%d%c",&year,&flage);
    //星期计算
    day=year-1+(year-1)/4-(year-1)/100+(year-1)/400+day;
    week=day%7;
    //闰年计算
    if((year%4==0&&year%100!=0)||year%400==0) {
        monthname[1]=29;
    }
    //如果输入回车键则结束输入显示年历
    if(flage!=32) {
        year_cd();
        return 0;
    }
    //输入空格则继续输入月份，显示月历
    scanf("%d",&month);
    month_cd(month);
    printf("%sn",weekname);
    for(i=0; i<6; i++) {
        for(j=0; j<7; j++) {
            if(years[month-1][i][j]==0) {
                printf("     ");
            } else {
                printf("%-5d",years[month-1][i][j]);
            }
        }
        printf("n");
    }
    return 0;
}

void month_cd(int months) {//months为要计算的月份
    int days=week;
    int nday=1;
    for(i=0; i
        days+=monthname[i];
    }
    days=days%7;
    for(i=0; i<6; i++) {
        for(j=days; j<7; j++) {
            days=0;
            years[months-1][i][j]=nday++;
            if(nday-1==monthname[months-1]) {
                return;
            }
        }
    }
}
void year_cd() {
    for(k=0; k<12; k++) {
        month_cd(k+1);
    }
    for(i=0; i<12; i+=2) {
        printf("%dt%st",i+1,weekname);
        printf("%dt%sn",i+2,weekname);
        for(j=0; j<6; j++) {
        printf("t");
            for(k=0; k<14; k++) {
            if(k==7)
            printf("tt");
                if(k<7) {
                    if(years[i][j][k]==0) {
                        printf("     ");
                        continue;
                    }
                    else {
                        printf("%-5d",years[i][j][k]);
                    }
                } else {
                    if(years[i+1][j][k-7]==0) {
                        printf("     ");
                        continue;
                    }
                    else {
                        printf("%-5d",years[i+1][j][k-7]);
                    }
                }
            }
            printf("n");
        }
    }
}