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43 lines
989 B
Java
43 lines
989 B
Java
import java.util.function.BiFunction;
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public class HillClimbing {
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public static double findMinimum(BiFunction<Double, Double, Double> f) {
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double curX = 0;
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double curY = 0;
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double curF = f.apply(curX, curY);
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for (double step = 1e6; step > 1e-7; ) {
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double bestF = curF;
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double bestX = curX;
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double bestY = curY;
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boolean find = false;
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for (int i = 0; i < 6; i++) {
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double a = 2 * Math.PI * i / 6;
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double nextX = curX + step * Math.cos(a);
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double nextY = curY + step * Math.sin(a);
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double nextF = f.apply(nextX, nextY);
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if (bestF > nextF) {
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bestF = nextF;
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bestX = nextX;
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bestY = nextY;
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find = true;
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}
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}
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if (!find) {
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step /= 2;
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} else {
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curX = bestX;
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curY = bestY;
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curF = bestF;
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}
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}
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System.out.println(curX + " " + curY);
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return curF;
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}
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// Usage example
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public static void main(String[] args) {
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System.out.println(findMinimum((x, y) -> (x - 2) * (x - 2) + (y - 3) * (y - 3)));
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}
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}
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