/**
 * @author Pacien TRAN-GIRARD
 * @author Timothée FLOURE
 */
public final class Seam {

    /**
     * Compute shortest path between {@code from} and {@code to}
     *
     * @param successors adjacency list for all vertices
     * @param costs      weight for all vertices
     * @param from       first vertex
     * @param to         last vertex
     * @return a sequence of vertices, or {@code null} if no path exists
     */
    public static int[] path(int[][] successors, float[] costs, int from, int to) {
        // TODO path
        return null;
    }

    /**
     * Find best seam
     *
     * @param energy weight for all pixels
     * @return a sequence of x-coordinates (the y-coordinate is the index)
     */
    public static int[] find(float[][] energy) {
        // TODO find
        return null;
    }

    /**
     * Draw a seam on an image
     *
     * @param image original image
     * @param seam  a seam on this image
     * @return a new image with the seam in blue
     */
    public static int[][] merge(int[][] image, int[] seam) {
        // Copy image
        int width = image[0].length;
        int height = image.length;
        int[][] copy = new int[height][width];
        for (int row = 0; row < height; ++row)
            for (int col = 0; col < width; ++col)
                copy[row][col] = image[row][col];

        // Paint seam in blue
        for (int row = 0; row < height; ++row)
            copy[row][seam[row]] = 0x0000ff;

        return copy;
    }

    /**
     * Remove specified seam
     *
     * @param image original image
     * @param seam  a seam on this image
     * @return the new image (width is decreased by 1)
     */
    public static int[][] shrink(int[][] image, int[] seam) {
        int width = image[0].length;
        int height = image.length;
        int[][] result = new int[height][width - 1];
        for (int row = 0; row < height; ++row) {
            for (int col = 0; col < seam[row]; ++col)
                result[row][col] = image[row][col];
            for (int col = seam[row] + 1; col < width; ++col)
                result[row][col - 1] = image[row][col];
        }
        return result;
    }

}