#include <stdio.h> // Date structure struct Date { int day; int month; int year; }; // Function to check leap year int isLeapYear(int year) { if ((year % 400 == 0) || (year % 4 == 0 && year % 100 != 0)) return 1; return 0; } // Function to validate date int isValidDate(struct Date d) { int daysInMonth[] = {0,31,28,31,30,31,30,31,31,30,31,30,31}; if (d.year < 1) return 0; if (d.month < 1 || d.month > 12) return 0; if (isLeapYear(d.year)) daysInMonth[2] = 29; if (d.day < 1 || d.day > daysInMonth[d.month]) return 0; return 1; } // Function to compare two dates int compareDates(struct Date d1, struct Date d2) { if (d1.year != d2.year) return d1.year < d2.year; if (d1.month != d2.month) return d1.month < d2.month; return d1.day < d2.day; } int main() { struct Date d1, d2; printf("Enter first date (DD MM YYYY): "); scanf("%d %d %d", &d1.day, &d1.month, &d1.year); printf("Enter second date (DD MM YYYY): "); scanf("%d %d %d", &d2.day, &d2.month, &d2.year); // Validate dates if (!isValidDate(d1) || !isValidDate(d2)) { printf("nInvalid date entered.n"); return 0; } // Compare dates if (compareDates(d1, d2)) printf("nFirst date comes before second date.n"); else if (compareDates(d2, d1)) printf("nSecond date comes before first date.n"); else printf("nBoth dates are the same.n"); return 0; }