快速切题 sgu115. Calendar 模拟 难度:0

115. Calendar

time limit per test: 0.25 sec. 
memory limit per test: 4096 KB

First year of new millenium is gone away. In commemoration of it write a program that finds the name of the day of the week for any date in 2001.

Input

Input is a line with two positive integer numbers N and M, where N is a day number in month M. N and M is not more than 100.

Output

Write current number of the day of the week for given date (Monday – number 1, … , Sunday – number 7) or phrase “Impossible” if such date does not exist.

Sample Input

21 10

Sample Output

7

#include <cstdio>
#include <cstring>
using namespace std;
const int date[12]={31,28, 31,30,31 ,30,31,31 ,30,31,30,31};
int main(){
    int day,month,orgdat=0;
    scanf("%d%d",&day,&month);month--;
    if((month<0||month>=12)||day<=0||day>date[month])puts("Impossible");
    else {for(int i=0;i<9;i++)orgdat+=date[i];
    orgdat+=21;
    orgdat=7-orgdat%7;
    for(int i=0;i<month;i++){
        orgdat+=date[i];
    }
    orgdat+=day;orgdat%=7;
    printf("%d\n",orgdat==0?7:orgdat);}
    return 0;
}