题解 | #计算日期到天数转换#

#include <iostream>
#include <string>
using namespace std;

int main(){
    string str[3];
    bool flag_year = false;
    int Num_mouth = 0;//每个月的天数
    int TotalDays = 0;
    
    for(int i = 0; i < 3; i++){
        cin >> str[i];
    }
    
    int year = (atoi)(str[0].c_str());
    int month = (atoi)(str[1].c_str());
    int day = (atoi)(str[2].c_str());

    if(year % 4 == 0&&year % 100 != 0){
        flag_year = true;      
    }
    else{
        flag_year = false;
    }
    
    if(year % 4 == 0 && year % 100 == 0)
    {
        if(year %400 == 0)
            flag_year = true;  
        else
            flag_year = false;
    }
    
    for(int i = 1; i < month; i++){
        if((i == 1) || (i == 3)||i == 5||i == 7||i == 8||i == 10||i == 12){
            Num_mouth = 31;
        }
        else if(i == 2 && flag_year == true){
            Num_mouth = 29;
        }
        else if(i == 2 && flag_year == false){
            Num_mouth = 28;
        }
        else{
            Num_mouth = 30;
        }
        TotalDays += Num_mouth;
    }
   
    cout << (TotalDays + day)<<endl;
}