add for rectangle

Author: houbb

src/main/java/com//houbb/leetcode/datastruct/sweepline/T223_rectangleArea_V1_overlapArea.java

@@ -0,0 +1,39 @@
+package com..houbb.leetcode.datastruct.sweepline;
+
+public class T223_rectangleArea_V1_overlapArea {
+
+
+public int computeArea(int ax1, int ay1, int ax2, int ay2, int bx1, int by1, int bx2, int by2) {
+int rect1 = rectangleArea(ax1, ay1, ax2, ay2);
+int rect2 = rectangleArea(bx1, by1, bx2, by2);
+
+int overlap = rectangleOverlapArea(new int[]{ax1, ay1, ax2, ay2}, new int[]{bx1, by1, bx2, by2});
+
+return rect1-overlap+rect2;
+}
+
+private int rectangleArea(int ax1, int ay1, int ax2, int ay2) {
+return (ax2-ax1) * (ay2-ay1);
+}
+
+public int rectangleOverlapArea(int[] rec1, int[] rec2) {
+// 计算交集矩形的左下角和右上角
+int x1 = Math.max(rec1[0], rec2[0]);
+int y1 = Math.max(rec1[1], rec2[1]);
+int x2 = Math.min(rec1[2], rec2[2]);
+int y2 = Math.min(rec1[3], rec2[3]);
+
+// 计算交集的宽度和高度
+int width = x2 - x1;
+int height = y2 - y1;
+
+// 如果交集的宽度和高度都大于 0，说明有重叠
+if (width > 0 && height > 0) {
+return width * height;
+}
+
+// 没有重叠
+return 0;
+}
+
+}

src/main/java/com//houbb/leetcode/datastruct/sweepline/T223_rectangleArea_V2_Sweepline.java

@@ -0,0 +1,52 @@
+package com..houbb.leetcode.datastruct.sweepline;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+public class T223_rectangleArea_V2_Sweepline {
+
+
+public static void main(String[] args) {
+computeArea(1,2,3,4,5,6,7,8);
+
+}
+
+public static int computeArea(int ax1, int ay1, int ax2, int ay2, int bx1, int by1, int bx2, int by2) {
+int[][] arr = new int[2][];
+arr[0] = new int[]{ax1, ay1, ax2, ay2};
+arr[1] = new int[]{bx1, by1, bx2, by2};
+Arrays.sort(arr, (o1, o2) -> o1[1] == o2[1] ? o1[3] - o2[3] : o1[1] - o2[1]);
+List<Integer> xList = Arrays.asList(ax1, ax2, bx1, bx2);
+Collections.sort(xList);
+int ans = 0;
+for (int i = 1; i < 4; i++) {
+int width = xList.get(i) - xList.get(i-1);
+for (int[] ints : getLine(xList.get(i-1), xList.get(i), arr)) {
+ans += width * (ints[1] - ints[0]);
+}
+}
+return ans;
+}
+
+private static List<int[]> getLine(int x1, int x2, int[][] arr) {
+List<int[]> list = new ArrayList<>();
+for (int[] ints : arr) {
+if (x1 >= ints[0] && x2 <= ints[2]) {
+if (list.isEmpty()) {
+list.add(new int[]{ints[1], ints[3]});
+} else {
+int[] tmp = list.get(list.size() - 1);
+if (tmp[1] < ints[1]) {
+list.add(new int[]{ints[1], ints[3]});
+} else if (tmp[1] < ints[3]) {
+tmp[1] = ints[3];
+}
+}
+}
+}
+return list;
+}
+
+}

src/main/java/com//houbb/leetcode/datastruct/sweepline/T836_rectangleOverlap_V1.java

@@ -0,0 +1,19 @@
+package com..houbb.leetcode.datastruct.sweepline;
+
+public class T836_rectangleOverlap_V1 {
+
+public static void main(String[] args) {
+T836_rectangleOverlap_V1 v1 = new T836_rectangleOverlap_V1();
+System.out.println(v1.isRectangleOverlap(new int[]{7,8,13,15}, new int[]{10,8,12,20}));
+}
+
+public boolean isRectangleOverlap(int[] rec1, int[] rec2) {
+// 判断 x 轴和 y 轴投影是否有交集
+boolean xOverlap = rec1[2] > rec2[0] && rec1[0] < rec2[2];
+boolean yOverlap = rec1[3] > rec2[1] && rec1[1] < rec2[3];
+
+// 两个投影都有交集才算重叠
+return xOverlap && yOverlap;
+}
+
+}

src/main/java/com//houbb/leetcode/datastruct/sweepline/T836_rectangleOverlap_V2_Sweepline.java

@@ -0,0 +1,64 @@
+package com..houbb.leetcode.datastruct.sweepline;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.TreeSet;
+
+public class T836_rectangleOverlap_V2_Sweepline {
+
+public boolean isRectangleOverlap(int[] rec1, int[] rec2) {
+// 如果 rec1 和 rec2 的 x 范围没有交集，直接返回 false
+if (rec1[2] <= rec2[0] || rec1[0] >= rec2[2] || rec1[3] <= rec2[1] || rec1[1] >= rec2[3]) {
+return false;
+}
+
+// 创建事件列表
+List<int[]> events = new ArrayList<>();
+
+// rec1 生成的事件
+events.add(new int[]{rec1[0], rec1[1], rec1[3], 1}); // 左边界
+events.add(new int[]{rec1[2], rec1[1], rec1[3], -1}); // 右边界
+
+// rec2 生成的事件
+events.add(new int[]{rec2[0], rec2[1], rec2[3], 1}); // 左边界
+events.add(new int[]{rec2[2], rec2[1], rec2[3], -1}); // 右边界
+
+// 按 x 坐标排序，若 x 相同，右边界事件优先
+events.sort((a, b) -> a[0] == b[0] ? b[3] - a[3] : a[0] - b[0]);
+
+// 使用一个优先队列来维护活动的 y 区间
+TreeSet<int[]> activeIntervals = new TreeSet<>((a, b) -> a[0] == b[0] ? Integer.compare(a[1], b[1]) : Integer.compare(a[0], b[0]));
+
+for (int[] event : events) {
+int x = event[0], y1 = event[1], y2 = event[2], type = event[3];
+
+if (type == 1) { // 左边界
+// 插入 y 区间
+activeIntervals.add(new int[]{y1, y2});
+
+// 检查当前是否有重叠
+if (hasOverlap(activeIntervals)) {
+return true;
+}
+} else { // 右边界
+// 移除 y 区间
+activeIntervals.remove(new int[]{y1, y2});
+}
+}
+
+return false;
+}
+
+// 检查是否有 y 区间重叠
+private boolean hasOverlap(TreeSet<int[]> activeIntervals) {
+int prevEnd = Integer.MIN_VALUE;
+for (int[] interval : activeIntervals) {
+if (interval[0] < prevEnd) {
+return true; // 有重叠
+}
+prevEnd = interval[1];
+}
+return false;
+}
+
+}

src/main/java/com//houbb/leetcode/datastruct/sweepline/T836_rectangleOverlap_V2_overlapArea.java

@@ -0,0 +1,25 @@
+package com..houbb.leetcode.datastruct.sweepline;
+
+public class T836_rectangleOverlap_V2_overlapArea {
+
+public boolean isRectangleOverlap(int[] rec1, int[] rec2) {
+// 计算交集矩形的左下角和右上角
+int x1 = Math.max(rec1[0], rec2[0]);
+int y1 = Math.max(rec1[1], rec2[1]);
+int x2 = Math.min(rec1[2], rec2[2]);
+int y2 = Math.min(rec1[3], rec2[3]);
+
+// 计算交集的宽度和高度
+int width = x2 - x1;
+int height = y2 - y1;
+
+// 如果交集的宽度和高度都大于 0，说明有重叠
+if (width > 0 && height > 0) {
+return true;
+}
+
+// 没有重叠
+return false;
+}
+
+}