NewDS

模板/排序/归并排序.cpp

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+#include <vector>
+#include <queue>
+#include <iostream>
+#include <tuple>
+using namespace std;
+
+void merge(vector<int>& nums, int l, int r){
+    int mid = (l + r) / 2;
+    int i = l, j = mid + 1;
+    vector<int> tmp;
+    while(i <= mid && j <= r){
+        if(nums[i] <= nums[j]) tmp.push_back(nums[i++]);
+        else tmp.push_back(nums[j++]);
+    }
+    while(i <= mid) tmp.push_back(nums[i++]);
+    while(j <= r) tmp.push_back(nums[j++]);
+
+    for(int x = l; x <= r; x++){
+        nums[x] = tmp[x - l];
+    }
+}
+
+void mergeSort(vector<int>& nums, int l, int r){
+    //回溯，后序
+    if(l >= r) return;
+    int mid = (l + r) / 2;
+    mergeSort(nums, l, mid);
+    mergeSort(nums, mid + 1, r);
+    //合并可以写在一起，但是分开清晰
+    merge(nums, l, r);
+}
+
+
+int main(){
+
+    return 0;
+}