2024/10/15灵茶题单 滑动窗口

src/main/java/com/cool/ling_cha_mount/sliding_windows/Num1888.java

@@ -0,0 +1,55 @@
+package com.cool.ling_cha_mount.sliding_windows;
+
+/**
+ * Created with IntelliJ IDEA.
+ *
+ * @Author: Cool
+ * @Date: 2024/10/15/14:27
+ * @Description:
+ */
+public class Num1888 {
+    public int minFlips1(String s) {
+        int len = s.length();
+        StringBuilder sb1 = new StringBuilder();
+        StringBuilder sb2 = new StringBuilder();
+        for (int i = 0; i < len; i++) {
+            sb1.append(i % 2 == 0 ? '1' : '0');
+            sb2.append(i % 2 == 0 ? '0' : '1');
+        }
+        int[] count1 = new int[len];
+        int[] count2 = new int[len];
+        for (int i = 0; i < len; i++) {
+            count1[i] = (i > 0 ? count1[i - 1] : 0) + (s.charAt(i) == sb1.charAt(i) ? 0 : 1);
+            count2[i] = (i > 0 ? count2[i - 1] : 0) + (s.charAt(i) == sb2.charAt(i) ? 0 : 1);
+        }
+        int res = Math.min(count1[len - 1], count2[len - 1]);
+        if (len % 2 == 1) {
+            for (int i = 0; i < len; i++) {
+                res = Math.min(res, count1[i] + count2[len - 1] - count2[i]);
+                res = Math.min(res, count2[i] + count1[len - 1] - count1[i]);
+            }
+            return res;
+        } else {
+            return res;
+        }
+    }
+    public int minFlips(String s) {
+        int len = s.length();
+        int[] target=new int[]{'0','1'};
+        int count=0;
+        for(int i=0;i<len;i++){
+            count+=s.charAt(i)^target[i%2];
+        }
+        int min=Math.min(count,len-count);
+        if(len%2==0){
+            return min;
+        }else{
+            for(int i=1;i<len;i++){
+                count-=s.charAt(i-1)^target[(i-1)%2];
+                count+=s.charAt(i-1)^target[i%2];
+                min=Math.min(min,Math.min(count,len-count));
+            }
+            return min;
+        }
+    }
+}