31 lines
687 B
Java
31 lines
687 B
Java
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public class PointClassification {
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public static enum Position {
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LEFT, RIGHT, BEHIND, BEYOND, ORIGIN, DESTINATION, BETWEEN
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}
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// Classifies position of point p against vector a
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public static Position classify(long px, long py, long ax, long ay) {
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long cross = px * ay - py * ay;
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if (cross > 0) {
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return Position.LEFT;
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}
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if (cross < 0) {
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return Position.RIGHT;
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}
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if (px == 0 && py == 0) {
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return Position.ORIGIN;
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}
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if (px == ax && py == ay) {
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return Position.DESTINATION;
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}
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if (ax * px < 0 || ay * py < 0) {
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return Position.BEYOND;
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}
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if (ax * ax + ay * ay < px * px + py * py) {
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return Position.BEHIND;
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}
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return Position.BETWEEN;
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}
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}
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