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Xor-Paths.cpp
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Xor-Paths.cpp
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#include<bits/stdc++.h>
using namespace std;
int di[2] = {0,1};
int dj[2] = {1,0};
long long bfs(vector<vector<int>> &mat, int i, int j, int n, int m, long long xori, long long k, unordered_map<string,int> &dp) {
if(i == n-1 && j == m-1) {
return (xori^mat[i][j]) == k;
}
string key = to_string(i) + to_string(j) + to_string(xori);
if(dp.find(key) != dp.end()) {
return dp[key];
}
if(i<0 || j<0 || i>=n || j>=m) {
return 0;
}
xori ^= mat[i][j];
return dp[key] = bfs(mat,i+1,j,n,m,xori,k,dp) + bfs(mat,i,j+1,n,m,xori,k,dp);
}
void solve() {
int n,m;
long long k;
cin >> n >> m >> k;
vector<vector<int>> mat(n, vector<int>(m,0));
unordered_map<string,int> dp;
for(int i=0; i<n; i++) {
for(int j=0; j<m; j++) {
cin >> mat[i][j];
}
}
int res = bfs(mat, 0, 0, n, m, (long long)0, k, dp);
cout << res << endl;
}
int main() {
solve();
return 0;
}