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;
}