a working non-recursive floodfill algorithm written in C?

Question

I\'ve been trying to find a working floodfill algorithm. Of the many algorithms I\'ve tried only the \'recursive line fill\' one behaves exactly as it should with the major

Answer 1

Below is my BFS based iterative c++ method for the flood fill problem:

// M is the input matrix, with every entry(pixel) have a color
// represented with an integer value.
// (x, y) row and column of seed point respectively
// k: The new color to fill the seed and its adjacent pixels
void floodFill(vector> &M, int x, int y, int k) {
    queue> nodeQ;
    nodeQ.push({x, y});
    int oldCol = M[x][y];
    while(!nodeQ.empty()) {
        pair currNode = nodeQ.front();
        nodeQ.pop();
        if(M[currNode.first][currNode.second] == oldCol) {
            M[currNode.first][currNode.second] = k;
            if(currNode.first > 0) nodeQ.push({currNode.first-1, currNode.second});
            if(currNode.first < (M.size()-1)) nodeQ.push({currNode.first+1, currNode.second});
            if(currNode.second > 0) nodeQ.push({currNode.first, currNode.second-1});
            if(currNode.second < (M[0].size()-1)) nodeQ.push({currNode.first, currNode.second+1});
        }
    }
}