weekly contest 316

Author: ZLBer

README.md

@@ -4,8 +4,10 @@ Record leetcode contest and ideas every week, and encourage yourself to think mo
 
 leetcode url: <https://leetcode.cn/u/cctest/>
 
+
+* ☀️ [weekly contest 316](src/main/java/weekly/wk316.java)     模拟 | gcd | 前缀和 | 分情况
 * ☀️ [weekly contest 315](src/main/java/weekly/wk315.java)     Hash表 | Hash表 | 暴力 | 双指针
-* 🐼 [weekly contest 314](src/main/java/weekly/wk312.java)     数组 | 异或运算 | 贪心+栈 | DP
+* 🐼 [weekly contest 314](src/main/java/weekly/wk314.java)     数组 | 异或运算 | 贪心+栈 | DP
 * 🐑 [weekly contest 312](src/main/java/weekly/wk312.java)     排序 | 脑筋急转弯 | 前缀和 | 并查集
 * 🐑 [weekly contest 311](src/main/java/weekly/wk311.java)     规律 | 滑动窗口 | 层序遍历 | 字典树
 * 🐑 [weekly contest 310](src/main/java/weekly/wk310.java)     排序、hash表 | 贪心 | 贪心、差分数组 | 线段树+区间最大值

src/main/java/weekly/wk316.java

@@ -0,0 +1,174 @@
+package weekly;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.time.LocalTime;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.PriorityQueue;
+
+public class wk316 {
+
+    //ranking: 942 / 6387
+
+    //又是这种时间题
+    public boolean haveConflict(String[] event1, String[] event2) {
+
+        return event1[0].compareTo(event2[1]) <= 0 && event1[1].compareTo(event2[0]) >= 0;
+
+    }
+
+//    boolean check(LocalTime a, LocalTime b, LocalTime c, LocalTime d) {
+//        if (b.compareTo(c) >= 0 && b.compareTo(d) <= 0) return true;
+//        if (d.compareTo(a) >= 0 && d.compareTo(b) <= 0) return true;
+//        return false;
+//    }
+
+
+    //暴力写的
+    public int subarrayGCD(int[] nums, int k) {
+        int ans = 0;
+        for (int i = 0; i < nums.length; i++) {
+            int g = 0;
+            for (int j = i; j < nums.length; j++) {
+                g = gcd(g, nums[j]);
+                if (g == k) ans += 1;
+                if (g % k > 0) break;
+            }
+        }
+        return ans;
+    }
+
+    int gcd(long a, long b) {
+        while (b != 0) {
+            long temp = a % b;
+            a = b;
+            b = temp;
+        }
+        return (int) a;
+    }
+
+
+    //前缀和容易考虑一点, 但也可以直接考虑sum
+  /*  public long minCost(int[] nums, int[] cost) {
+        long[][] pack = new long[nums.length][2];
+        for (int i = 0; i < nums.length; i++) {
+            pack[i] = new long[]{nums[i], cost[i]};
+        }
+        Arrays.sort(pack, (a, b) -> Long.compare(a[0], b[0]));
+
+        long res = 0;
+        for (int i = 1; i < pack.length; i++) {
+            res += (pack[i][0] - pack[0][0]) * pack[i][1];
+        }
+        for (int i = 1; i < pack.length; i++) {
+            pack[i][1] += pack[i - 1][1];
+        }
+        long ans = Long.MAX_VALUE;
+        for (int i = 1; i < pack.length; i++) {
+            res += (pack[i][0] - pack[i - 1][0]) * (pack[i - 1][1] - (pack[nums.length - 1][1] - pack[i - 1][1]));
+            ans = Math.min(ans, res);
+        }
+        return ans;
+    }*/
+    //不用前缀和
+    public long minCost(int[] nums, int[] cost) {
+        long[][] pack = new long[nums.length][2];
+        for (int i = 0; i < nums.length; i++) {
+            pack[i] = new long[]{nums[i], cost[i]};
+        }
+        Arrays.sort(pack, (a, b) -> Long.compare(a[0], b[0]));
+
+        long res = 0;
+        long sumCost=pack[0][1];
+        for (int i = 1; i < pack.length; i++) {
+            res += (pack[i][0] - pack[0][0]) * pack[i][1];
+            sumCost+=pack[i][1];
+        }
+        long ans = res;
+        for (int i = 1; i < pack.length; i++) {
+             sumCost-=2*pack[i-1][1];
+            res -= (pack[i][0] - pack[i - 1][0]) * sumCost;
+            ans = Math.min(ans, res);
+        }
+        return ans;
+    }
+
+
+    //分奇数偶数考虑,要分很多情况
+   /* public long makeSimilar(int[] nums, int[] target) {
+        List<Integer> nums1 = new ArrayList<>();
+        List<Integer> nums2 = new ArrayList<>();
+        List<Integer> target1 = new ArrayList<>();
+        List<Integer> target2 = new ArrayList<>();
+        Arrays.sort(nums);
+        Arrays.sort(target);
+        for (int i = 0; i < nums.length; i++) {
+            if (nums[i] % 2 == 1) {
+                nums1.add(nums[i]);
+            } else {
+                nums2.add(nums[i]);
+            }
+            if (target[i] % 2 == 1) {
+                target1.add(target[i]);
+            } else {
+                target2.add(target[i]);
+            }
+        }
+        long[] a = help(nums1, target1, 0, 0);
+        long[] b = help(nums2, target2, a[1], a[2]);
+        System.out.println(a + " " + b);
+        return a[0] + b[0];
+    }
+
+    long[] help(List<Integer> nums, List<Integer> target, long up, long down) {
+        long count = 0;
+        for (int i = 0; i < nums.size(); i++) {
+            int a = nums.get(i), b = target.get(i);
+            if (a > b) {
+                int need = (a - b) / 2;
+                if (down >= need) {
+                    down -= need;
+                } else {
+                    count += (need - down);
+                    up += (need - down);
+                    down = 0;
+                }
+
+            } else if (a < b) {
+                int need = (b - a) / 2;
+                if (up >= need) {
+                    up -= need;
+                } else {
+                    count += (need - up);
+                    down += (need - up);
+                    up = 0;
+                }
+            }
+        }
+        return new long[]{count, up, down};
+    }*/
+
+
+    //大佬的做法,把奇数变成负数，区分奇偶，然后计算绝对值差，最后/4即可，因为题目说一定有答案
+    public long makeSimilar(int[] nums, int[] target) {
+        f(nums);
+        f(target);
+        long ans = 0L;
+        for (int i = 0; i < nums.length; ++i)
+            ans += Math.abs(nums[i] - target[i]);
+        return ans / 4;
+    }
+
+    private void f(int[] a) {
+        // 由于元素都是正数，把奇数变成相反数，这样排序后奇偶就自动分开了
+        for (int i = 0; i < a.length; ++i)
+            if (a[i] % 2 != 0) a[i] = -a[i];
+        Arrays.sort(a);
+    }
+
+}