UVa : 11957 (Checkers)



// http://uva.onlinejudge.org/external/119/11957.html
// Runtime: 0.024s
// Tag: Adhoc 

// @BEGIN_OF_SOURCE_CODE

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cctype>
#include <stack>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <sstream>
#include <cmath>
#include <bitset>
#include <utility>
#include <set>
#include <numeric>

#define INF_MAX 2147483647
#define INF_MIN -2147483647
#define pi acos(-1.0)
#define N 1000000
#define LL long long

#define For(i, a, b) for( int i = (a); i < (b); i++ )
#define Fors(i, sz) for( size_t i = 0; i < sz.size (); i++ )
#define Fore(it, x) for(typeof (x.begin()) it = x.begin(); it != x.end (); it++)
#define Set(a, s) memset(a, s, sizeof (a))
#define Read(r) freopen(r, "r", stdin)
#define Write(w) freopen(w, "w", stdout)

int dr [] = {-1, -1, 0, 1, 1, 1, 0, -1};
int dc [] = {0, 1, 1, 1, 0, -1, -1, -1};

using namespace std;

char mat [100 + 5] [100 + 5];
int paths [100 + 5] [100 + 5];
int n;

void reset ()
{
    for ( int i = 0; i < 105; i++ )
        for ( int j = 0; j < 105; j++ ) paths [i] [j] = 0;
}

void inc (int r, int c)
{
    paths [r] [c] %= 1000007;

    if ( r + 1 < n && c + 1 < n )
        if ( mat [r + 1] [c + 1] != 'B' ) paths [r + 1] [c + 1] = (paths [r + 1] [c + 1] + paths [r] [c]) % 1000007;
        else
            if ( r + 2 < n && c + 2 < n )
                if ( mat [r + 2] [c + 2] != 'B' ) paths [r + 2] [c + 2] = (paths [r + 2] [c + 2] + paths [r] [c]) % 1000007;

    if ( r + 1 < n && c - 1 >= 0 )
        if ( mat [r + 1] [c - 1] != 'B' ) paths [r + 1] [c - 1] = (paths [r + 1] [c - 1] + paths [r] [c]) % 1000007;
        else
            if ( r + 2 < n && c - 2 >= 0 )
                if ( mat [r + 2] [c - 2] != 'B' ) paths [r + 2] [c - 2] = (paths [r + 2] [c - 2] + paths [r] [c]) % 1000007;
}

int main ()
{
    // Read ("in.in");

    int testCase; scanf ("%d", &testCase);
    int cases = 0;

    while ( testCase-- ) {
        reset ();
        scanf ("%d", &n);

        for ( int i = 0; i < n; i++ ) scanf ("%s", mat [i]);

        for ( int i = 0; i < n; i++ )
            if ( mat [0] [i] != 'B' ) paths [0] [i] = 1;

        for ( int i = 0; i < n; i++ )
            for ( int j = 0; j < n; j++ ) inc (i, j);

        for ( int i = 0; i < n; i++ )
            for ( int j = 0; j < n; j++ )
                if ( mat [i] [j] == 'W' ) printf ("Case %d: %d\n", ++cases, paths [i] [j] % 1000007);
    }

	return 0;
}

// @END_OF_SOURCE_CODE

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