c++ - 在网格中设置新值

Question

我正在做的运动（生活游戏）有一个奇怪的问题。在代码的中间部分，行 nextgeneration.set(livex, livey, live); 导致程序停止运行。有任何想法吗？

int lifeGenerator(Grid<int>& nextgeneration, Grid<int>& birthsanddeaths) {
    for (int deadx = 0; deadx < nrows; deadx++) {
        for (int deady = 0; deady < ncols; deady++) {
            int dead = birthsanddeaths.get(deadx, deady);
            if (dead == -3) {
                nextgeneration.set(deadx, deady, 0);
                }
            }
        }
    for (int livex = 0; livex < nrows; livex++) {
        for (int livey = 0; livey < ncols; livey++) {
            int live = nextgeneration.get(livex, livey);
                if (live > 0 && live < kMaxAge) {
                live++;
                nextgeneration.set(livex, livey, live);// this doesnt work....
                }
            }
        }
    for (int newx = 0; newx < nrows; newx++) {
        for (int  newy = 0; newy < ncols; newy++) {
            int born = birthsanddeaths.get(newx, newy);
            if (born == 3) {
                    nextgeneration.set(newx, newy, 1);
            }
        }
    }
    return 0;
}