将循环重写为单行循环

Question

是否可以将以下循环重写为单行循环？

for (int i = 0; i < points.length; i++) {
    for (int j = i + 1; j < points.length; j++) {
        if (points[i].equals(points[j])) {
            return "Two vertices coincide therefore a polygon can't be formed";
        }

    }
}
for (int i = 0; i < points.length; i++) {
    for (int j = i + 1; j < points.length; j++) {
        if (points[i].isOnLineSegment(points[j], points[j + 1])) {
            return "There's a vertex on an edge therefore a polygon can't be formed";
        }
    }
}

我想写后置条件，但除了可能将每个循环重写为一行之外，我不知道如何做到这一点。

Answer 1

你在寻找：

for (int i = 0; i < points.length; i++) {
    for (int j = i + 1; j < points.length; j++) {
        if (points[i].equals(points[j])) {
            return "Two vertices coincide therefore a polygon can't be formed";
        }
        if (points[i].isOnLineSegment(points[j], points[j + 1])) {
            return "There's a vertex on an edge therefore a polygon can't be formed";
        }
    }
}

注意：如评论中所述，您在此处的操作points[j + 1] ，如果未找到结果，可能会抛出ArrayIndexOutOfBoundsException ，在这种情况下，我建议使用：

if (j + 1 < points.length && points[i].isOnLineSegment(points[j], points[j + 1])) {