目前正在看《大話數據結構》,其中介紹了普利姆算法,本身對算法理解能力太差,可以手寫求出最小生成樹,可是寫出算法代碼卻無從下手,看了幾遍書中的算法,也沒看明白,最後經過本身的理解寫了如下代碼,事後再去搞定書中的算法。
java
public class MinTree { private static final int max = 65535; private static final int VertrixCount = 9; private static int[][] martrix = new int[][] { { 0, 10, max, max, max, 11, max, max, max }, { 10, 0, 18, max, max, max, 16, max, 12 }, { max, max, 0, 22, max, max, max, max, 8 }, { max, max, 22, 0, 20, max, max, 16, 21 }, { max, max, max, 20, 0, 26, max, 7, max }, { 11, max, max, max, 26, 0, 17, max, max }, { max, 16, max, max, max, 17, 0, 19, max }, { max, max, max, 16, 7, max, 19, 0, max }, { max, 12, 8, 21, max, max, max, max, 0 } }; public void createMinTree() { int[] nodes = new int[VertrixCount]; for (int i = 0; i > VertrixCount; i++) { nodes[i] = 0; } nodes[0] = 1; while (true) { int min_out = max; int x_out = 0; int y_out = 0; for (int x = 0; x < VertrixCount; x++) { if (nodes[x] == 0) { continue; } int min = max; int index = 0; for (int y = 0; y < VertrixCount; y++) { if (nodes[y] != 0) { continue; } if (martrix[x][y] != 0 && martrix[x][y] < max) { if (min > martrix[x][y]) { min = martrix[x][y]; index = y; } } } if (min_out > min) { min_out = min; x_out = x; y_out = index; } } nodes[y_out] = 1; System.out.println(String.format("(%d,%d)", x_out, y_out)); boolean flag = false; for (int i = 0; i < VertrixCount; i++) { if (nodes[i] == 0) { flag = true; } } if (flag == false) { return; } } } }