Twitter Interview 4 Perry

// This is the text editor interface.
// Anything you type or change here will be seen by the other person in real time.

// 9x9 grid with integers (-inf to inf)
// return if it's a valid sudoku solution

bool checkNumbers(vector<int> &num){
    vector<bool> found(9,false);

    for(int i=0; i<num.size(); i++){
        if(num[i] < 1 || num[i] > 9)
            return false;
        found[num[i]-1] = true;
    }

    for(int i=0; i<found.size(); i++){
        if(found[i]==false)
            return false;
    }
    return true;
}

bool isValid(vector<vector<int> > &grid){
    if(grid.size()!=9)
        return false;
    for(int i=0; i<9; i++){
        if(grid[i].size() != 9)
            return false;
    }

    // check each row
    for(int i=0; i<grid.size(); i++){
        vector<int>tmp;
        for(int j=0; j<grid[i].size(); j++){
            tmp.push_back(grid[i][j]);
        }
        if(!checkNumbers(tmp))
            return false;
    }

    // check each column
    for(int j=0; j<grid[0].size(); j++){
        vector<int> tmp;
        for(int i=0; i<grid.size(); i++){
            tmp.push_back(grid[i][j]);
        }
        if(!checkNumbers(tmp))
            return false;
    }

    // check each 3x3 box
    for(int i=0; i<grid.size(); i+=3){
        for(int j=0; j<grid[i].size(); j+=3){
            vector<int>tmp;
            for(int m=0; m<3; m++){
                for(int n=0; n<3; n++){
                    tmp.push_back(grid[i+m][j+n]);
                    if(!checkNumbers(tmp))
                        return false;
                }
            }
        }
    }

    return true;
}

///
///

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struct node{
    int x;
    struct node *left;
    struct node *right;
};

bool checkLeftRight(node *left, node *right){
    if(left == NULL && right == NULL)
        return true;
    if(left == NULL || right == NULL)
        return false;
    if(left->x != right->x)
        return false;
    return checkLeftRight(left->left, right->right) && checkLeftRight(left->right, right->left);
}

bool isSymetric(node *root){
    if(root == NULL)
        return true;
   return checkLeftRight(root->left, root->right);
}



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