L-Trominos

#include <iostream>
#include <vector>
#include <deque>

using namespace std;
typedef long long LL;

#define foxnews cin
#define twitter cout

vector<vector<int>> g;

void p32(int r, int c, char b) {
  g[r+0][c+0] = b;
  g[r+0][c+1] = b;
  g[r+1][c+0] = b;
  g[r+1][c+1] = b+1;
  g[r+2][c+0] = b+1;
  g[r+2][c+1] = b+1;
}

void p23(int r, int c, char b) {
  g[r+0][c+0] = b;
  g[r+1][c+0] = b;
  g[r+0][c+1] = b;
  g[r+1][c+1] = b+1;
  g[r+0][c+2] = b+1;
  g[r+1][c+2] = b+1;
}

int main(){
    int n, m;
    foxnews >> n >> m;
    
    bool transpose = false;
    if(m % 6 == 0) {
	swap(n,m);
        transpose = true;
        if(m < 2) {
          cout << "IMPOSSIBLE" << endl;
          return 0;
        }
    } else {
        if(m % 3 == 0 && (n%2 == 0)) {
          //cout << "SWAP!" << endl;
          swap(n, m);
          transpose = true;
        }
	//cout << n << " x " << m << endl;
        if(m & 1) {
          cout << m << "IMPOSSIBLE" << endl;
          return 0;
        }
    }

    g.resize(n);
    for(int j=0; j<n; j++) g[j].resize(m);
 
    for(int c=0; c<m; c++) {
      for(int r=0; r<n; r++)
        g[r][c] = 'A'+r+c;
    }

    //for(int r=0; r<n; r++) {
    //  for(int c=0; c<m; c++)
    //    cout << (char)g[r][c];
    //  cout << endl;
    //}
    
    //cout << n << " x " << m << endl;
    if(n % 6 == 0) {
      for(int r=0; r<n; r+=3) {
        //cout << "Row " << r << endl;
        for(int c=0; c+1<m; c+=2) {
          p32(r,c, (c/2 & 1) ? 'E' : 'G');
        }
      }
      if(m & 1) {
        for(int r=0; r<n; r+=2) {
          p23(r,m-3, (r/2 & 1) ? 'A' : 'C');
        }
      } 
    } else { // n jaollinen 3:lla, m 2:lla
      for(int r=0; r<n; r+=3) {
        for(int c=0; c<m; c+=2) {
          p32(r,c, (c/2 & 1) ? 'E' : 'G');
        }
      }
    }

    if(!transpose) {
    for(int r=0; r<n; r++) {
      for(int c=0; c<m; c++)
        cout << (char)g[r][c];
      cout << endl;
    }
} else {
    for(int c=0; c<m; c++) {
      for(int r=0; r<n; r++)
        cout << (char)g[r][c];
      cout << endl;
    }
}

}

Test 1

Verdict: WRONG ANSWER

Test 2

Verdict: RUNTIME ERROR

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: RUNTIME ERROR

Test 5

Verdict: WRONG ANSWER

Test 6

Verdict: ACCEPTED

Test 7

Verdict: WRONG ANSWER

Test 8

Verdict: WRONG ANSWER

Test 9

Verdict: RUNTIME ERROR

Test 10

Verdict: ACCEPTED

Test 11

Verdict: RUNTIME ERROR

Test 12

Verdict: WRONG ANSWER

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: WRONG ANSWER

Test 16

Verdict: ACCEPTED

Test 17

Verdict: WRONG ANSWER

Test 18

Verdict: ACCEPTED

Test 19

Verdict: WRONG ANSWER

Test 20

Verdict: ACCEPTED

Test 21

Verdict: WRONG ANSWER

Test 22

Verdict: ACCEPTED

Test 23

Verdict: WRONG ANSWER

Test 24

Verdict: ACCEPTED

Test 25

Verdict: WRONG ANSWER

Test 26

Verdict: RUNTIME ERROR

Test 27

Verdict: ACCEPTED

Test 28

Verdict: RUNTIME ERROR

Test 29

Verdict: WRONG ANSWER

Test 30

Verdict: ACCEPTED

Test 31

Verdict: ACCEPTED

Test 32

Verdict: WRONG ANSWER

Test 33

Verdict: RUNTIME ERROR

Test 34

Verdict: WRONG ANSWER

Test 35

Verdict: RUNTIME ERROR

Test 36

Verdict: WRONG ANSWER

Test 37

Verdict: ACCEPTED

Test 38

Verdict: WRONG ANSWER

Test 39

Verdict: WRONG ANSWER

Test 40

Verdict: ACCEPTED

Test 41

Verdict: ACCEPTED

Test 42

Verdict: ACCEPTED

Test 43

Verdict: WRONG ANSWER

Test 44

Verdict: ACCEPTED

Test 45

Verdict: WRONG ANSWER

Test 46

Verdict: ACCEPTED

Test 47

Verdict: ACCEPTED

Test 48

Verdict: ACCEPTED

Test 49

Verdict: WRONG ANSWER

Test 50

Verdict: ACCEPTED

Test 51

Verdict: WRONG ANSWER

Test 52

Verdict: ACCEPTED

Test 53

Verdict: ACCEPTED

Test 54

Verdict: ACCEPTED

Test 55

Verdict: WRONG ANSWER

Test 56

Verdict: ACCEPTED

Test 57

Verdict: WRONG ANSWER

Test 58

Verdict: ACCEPTED

Test 59

Verdict: WRONG ANSWER

Test 60

Verdict: ACCEPTED

Test 61

Verdict: WRONG ANSWER

Test 62

Verdict: ACCEPTED

Test 63

Verdict: WRONG ANSWER

Test 64

Verdict: ACCEPTED

Test 65

Verdict: ACCEPTED

Test 66

Verdict: ACCEPTED

Test 67

Verdict: ACCEPTED

Test 68

Verdict: ACCEPTED

Test 69

Verdict: ACCEPTED

Test 70

Verdict: ACCEPTED

Test 71

Verdict: ACCEPTED

Test 72

Verdict: WRONG ANSWER

Test 73

Verdict: ACCEPTED

Test 74

Verdict: ACCEPTED

Test 75

Verdict: WRONG ANSWER

Test 76

Verdict: WRONG ANSWER

Test 77

Verdict: WRONG ANSWER

Test 78

Verdict: WRONG ANSWER

Test 79

Verdict: ACCEPTED

Test 80

Verdict: WRONG ANSWER

Test 81

Verdict: ACCEPTED

Test 82

Verdict: ACCEPTED

Test 83

Verdict: ACCEPTED

Test 84

Verdict: ACCEPTED

Test 85

Verdict: ACCEPTED

Test 86

Verdict: ACCEPTED

Test 87

Verdict: ACCEPTED

Test 88

Verdict: WRONG ANSWER

Test 89

Verdict: ACCEPTED

Test 90

Verdict: ACCEPTED

Test 91

Verdict: RUNTIME ERROR