三种方式实现输出计算该日在本年中是第几天

#define  _CRT_SECURE_NO_WARNINGS

#include<stdio.h>

#include<string.h>

typedef struct time { //这里的time是结构体名字

int year;

int month;

int day;

}Time;

int main() {

Time s1 ;//S3 s1; struct time s1均可

scanf("%d%d%d", &s1.year, &s1.month, &s1.day);

int sum = 0;

//第一种方法

int mt[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };

if (s1.year % 4 == 0 && s1.year % 100 != 0 || s1.year % 400 == 0) {

mt[1] = 29;

}

for (int i = 1; i < s1.month ;i++) {//for(int i = 0; i < s1.month-1;i++){ sum += mt[i]; } 两种写法均可以

sum += mt[i-1];

}

sum += s1.day;

/*

第二种方法

int mo[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };

for (int i = 0; i < s1.month - 1;i++) {

sum += mo[i];

}

sum += s1.day;

if (s1.year % 4 == 0 && s1.year % 100 != 0 || s1.year % 400 == 0) {

sum = sum + 1;

}*/

/*

第三种方法

for (int i = 1;i <= s1.month;i++) {

if (s1.month == i) {

sum += s1.day;

break;

}

else {

switch (i)

{

case 1:

case 3:

case 5:

case 7:

case 8:

case 10:

case 12:

sum += 31;

break;

case 2:

if (s1.year % 4 == 0 && s1.year % 100 != 0 || s1.year % 400 == 0) {

// 是闰年

sum += 29;

}

else {

// 不是闰年

sum += 28;

}

break;

case 4:

case 6:

case 9:

case 11:

sum += 30;

break;

}

}

}*/

printf("%d\n", sum);

}