周赛258

src/main/java/com/code/leet/week/Solution258.java

@@ -0,0 +1,40 @@
+package com.code.leet.week;
+
+import javafx.util.Pair;
+
+import java.util.*;
+
+/**
+ * @description:
+ * @author: Administrator
+ * @date: 2021/8/22-10:29
+ */
+public class Solution258 {
+    public static void main(String[] args) {
+        Solution258 solution = new Solution258();
+    }
+
+    public String reversePrefix(String word, char ch) {
+        int index = word.indexOf(ch);
+        if (index > 0) {
+            StringBuilder str = new StringBuilder(word.substring(0, index + 1));
+            word = str.reverse() + word.substring(index + 1);
+        }
+        return word;
+    }
+
+    public long interchangeableRectangles(int[][] rectangles) {
+        Map<Double, Integer> map = new HashMap<>();
+        for (int[] rectangle : rectangles) {
+            double key = (double) rectangle[1] / rectangle[0];
+            map.put(key, map.getOrDefault(key, 0) + 1);
+        }
+        long sum = 0;
+        for (double key : map.keySet()) {
+            if (map.get(key) > 1) {
+                sum += (long) map.get(key) * (map.get(key) - 1) / 2;
+            }
+        }
+        return sum;
+    }
+}