How to initialize a static array to certain value in a function in c++?

Question

I am trying to init a static array in a function.

int query(int x, int y) {
    static int res[100][100]; // need to          


        

Answer 1

You can do it for example the following way by means of introducing one more static variable

int query(int x, int y) {
    static bool initialized;
    static int res[100][100]; // need to be initialized to -1

    if ( not initialized )
    {
        for ( auto &row : res )
        {
            for ( auto &item : row ) item = -1;
        }

        initialized = true;
    }        

    if (res[x][y] == -1) {
        res[x][y] = time_consuming_work(x, y);
    }
    return res[x][y];
}