if (i == 0 && j == 0) return matrix[i][j];

if (mem[i][j] > 0) return mem[i][j];

int minLeft = MAX_NUM;

if (j - 1 >= 0) {

minLeft = minDist(i, j - 1);

}

int minUp = MAX_NUM;

if (i - 1 >= 0) {

minUp = minDist(i - 1, j);

}

int currMinDist = min(minLeft, minUp) + matrix[i][j];

mem[i][j] = currMinDist;

return currMinDist;

int ret = minDist(N - 1, N - 1);

cout << "结果为:" << ret << endl;

}