class Solution {
    public int[] shortestAlternatingPaths(int n, int[][] red_edges, int[][] blue_edges) {
        tests();
        return run(n, red_edges, blue_edges);
    }

    private int[] run(int n, int[][] red_edges, int[][] blue_edges) {
        return null;
    }

    private void tests() {
        a(3, new int[][] {{0,1}, {1,2}}, new int[][] {}, new int[] {0, 1, -1});
        a(3, new int[][] {{0,1}, {2,1}}, new int[][] {}, new int[] {0, 1, -1});
        a(3, new int[][] {{1,0}, {2,1}}, new int[][] {}, new int[] {0, -1, -1});
        a(3, new int[][] {{0,1}, {1,2}}, new int[][] {}, new int[] {0, 1, 2});
        a(3, new int[][] {{0,1}, {0,2}}, new int[][] {}, new int[] {0, 1, 1});
        a(3, new int[][] {{0,1}, {1,2}}, new int[][] {{1,1}}, new int[] {0, 1, 3});
        a(7, new int[][] {{0,1},{0,2},{2,3},{3,4},{4,4},{0,6}}, new int[][] {{2,1},{0,4},{4,3},{0,6}}, new int[] {0,1,1,3,1,-1,1});
    }

    private void a(int n, int[][] red_edges, int[][] blue_edges, int[] expected) {
        int[] actual = run(n, red_edges, blue_edges);
        String actualS = Arrays.toString(actual);
        String expectedS = Arrays.toString(expected);
        if (actual != expected) System.out.println("FAILED " + n + " " + twods(red_edges)
            + " "+ twods(blue_edges) + " was " + actualS + " expected " + expectedS);
    }

    private String twods(int[][] a) {
        StringBuilder sb = new StringBuilder();
        sb.append("[");
        for (int i = 0; i < a.length; i++)
            sb.append(Arrays.toString(a[i]) + (i != a.length - 1 ? ",": ""));
        sb.append("]");
        return sb.toString();
    }
}