实现日历功能，输入年份月份，输出日历
#includeint leap_year(int year){if(year % 4 == 0 && year % 100 != 0 || year % 400 == 0){return 1;}else{return 0;}}int determine_year_month_day(int *day,int month,int year){if(month != 2){return day[month - 1];}else{return 28 + leap_year(year);}}int date_of_1900(int month,int year,int *day){int i,j;int sum = 0;for(i = 1900;i < year;++i){if(leap_year(i) == 1){sum += 366;}else if(leap_year(i) == 0){sum += 365;}}for(j = 1;j < month;++j){sum += determine_year_month_day(day,j,i);}return sum;}int printf_calendar(int month,int year,int *day){int i,j,max;max = determine_year_month_day(day,month,year);printf(" %d月%d年 \n",month,year);printf("一二三四五六日\n");int min = date_of_1900(month,year,day) % 7;for(j = min;j > 0;--j){printf("");}for(i = 1;i <= max;++i){printf("%4d",i);if((i+min) % 7 == 0){putchar('\n');}}}int main(void){int year,month;int day[] = {31,28,31,30,31,30,31,31,30,31,30,31};printf("Please enter the year and month you want to query:");scanf("%d %d",&year,&month);if(month > 12 || month < 1){printf("Input Error!\n");}printf_calendar(month,year,day);putchar('\n');return 0;}实现的结果如图所示：
