C language introduction practice (8): switch case calculates the month, year and day of the next day (normal year / leap year calculation)

This is a 《C Language introduction practice 》 Series No 8 piece .
Last one ：C Language introduction practice (7)：switch-case Calculate the number of days in the year （ Ordinary year / Leap year calculations ）

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subject

For any entered date （ Use variables for month, year and day respectively y、m、d Express ）, Find the date of the next day . The result is yyyy/MM/dd Format output .

Tips

1. Consider the end of the month 、 End of year and leap year .
2. To calculate the number of days in the current month, you can use switch Statements for .

requirement

Example of input / output format 1：

Input ：2019 12 31< enter >
Output ：2020/01/01

Example of input / output format 2：

Input ：2020 02 28< enter >
Output ：2020/02/29

Pre knowledge

A hundred years ： Can be 400 Divided by leap years ; Not a whole century ： Can be 4 Divided by leap year .

Ordinary year 365 God , February is 28 God .

Leap year is 366 God , February is 29 God .

Reference code

#include <stdio.h>
int main() {
    
	int y,m,d;
	scanf("%d %d %d", &y, &m, &d);
	
	//  Ordinary year 2 month 28 God 
	int daysInFebruary = 28;
	//  If it's a leap year , Then February 29 God  
	if(y%400==0 || (y%100!=0 && y%4==0)) {
    
		daysInFebruary = 29;
	}
	//  Calculate the maximum number of days in the current month  
	int maxDays;
	switch(m) {
    
		case 1:
		case 3:
		case 5:
		case 7:
		case 8:
		case 10:
		case 12:
			maxDays = 31;
			break;
		case 2:
			maxDays = daysInFebruary;
			break;
		default:
			maxDays = 30;
			break;
	} 
	
	//  Processing days +1, If the number of days exceeds the maximum number of days in the month 
	//  Continue processing month +1, If the month exceeds the maximum month of the year 
	//  Then year +1
	d += 1;
	if(d > maxDays) {
    
		//  Exceed the maximum number of days in the current month 1 God , Count as next month 1 Number  
		d = 1;
		//  month +1
		m += 1;
		//  Month exceeds , Then year +1 
		if(m > 12) {
    
			m = 1;
			y += 1;
		} 
	}
	printf("%d/%02d/%02d", y, m, d); 
	
	return 0;
} 

Code duplicate

be familiar with switch-case Usage of , Note that each branch requires break.

The header file stdio.h Declarative scanf() and printf() It is used to process standard input and output in the standard library Library function .