-

Author: liuchuo

AdvancedLevel_C++/1020. Tree Traversals (25).cpp

@@ -1,20 +1,14 @@
-#include <iostream>
-#include <algorithm>
+#include <cstdio>
 #include <vector>
+#include <map>
 using namespace std;
-struct node {
-    int index, value;
-};
-bool cmp(node a, node b) {
-    return a.index < b.index;
-}
 vector<int> post, in;
-vector<node> ans;
+map<int, int> level;
 void pre(int root, int start, int end, int index) {
-    if (start > end) return;
+    if(start > end) return ;
     int i = start;
-    while (i < end && in[i] != post[root]) i++;
-    ans.push_back({index, post[root]});
+    while(i < end && in[i] != post[root]) i++;
+    level[index] = post[root];
     pre(root - 1 - end + i, start, i - 1, 2 * index + 1);
     pre(root - 1, i + 1, end, 2 * index + 2);
 }
@@ -23,13 +17,11 @@ int main() {
     scanf("%d", &n);
     post.resize(n);
     in.resize(n);
-    for (int i = 0; i < n; i++) scanf("%d", &post[i]);
-    for (int i = 0; i < n; i++) scanf("%d", &in[i]);
-    pre(n - 1, 0, n - 1, 0);
-    sort(ans.begin(), ans.end(), cmp);
-    for (int i = 0; i < ans.size(); i++) {
-        if (i != 0) cout << " ";
-        cout << ans[i].value;
-    }
+    for(int i = 0; i < n; i++) scanf("%d", &post[i]);
+    for(int i = 0; i < n; i++) scanf("%d", &in[i]);
+    pre(n-1, 0, n-1, 0);
+    auto it = level.begin();
+    printf("%d", it->second);
+    while(++it != level.end()) printf(" %d", it->second);
     return 0;
 }

CCCC-GPLT/L2-002. 链表去重.cpp

@@ -4,10 +4,7 @@
 using namespace std;
 const int maxn = 100000;
 struct NODE {
-    int address;
-    int key;
-    int next;
-    int num;
+    int address, key, next, num;
 }node[maxn];
 bool exist[maxn];
 int cmp1(NODE a, NODE b){
@@ -45,4 +42,4 @@ int main() {
         }
     }
     return 0;
-}
+}

CCCC-GPLT/L2-006. 树的遍历.cpp

@@ -1,7 +1,9 @@
 #include <cstdio>
 #include <vector>
+#include <map>
 using namespace std;
-vector<int> post, in, level(100000, -1);
+vector<int> post, in;
+map<int, int> level;
 void pre(int root, int start, int end, int index) {
     if(start > end) return ;
     int i = start;
@@ -11,21 +13,15 @@ void pre(int root, int start, int end, int index) {
     pre(root - 1, i + 1, end, 2 * index + 2);
 }
 int main() {
-    int n, cnt = 0;
+    int n;
     scanf("%d", &n);
     post.resize(n);
     in.resize(n);
     for(int i = 0; i < n; i++) scanf("%d", &post[i]);
     for(int i = 0; i < n; i++) scanf("%d", &in[i]);
     pre(n-1, 0, n-1, 0);
-    for(int i = 0; i < level.size(); i++) {
-        if(level[i] != -1 && cnt != n - 1) {
-            printf("%d ", level[i]);
-            cnt++;
-        } else if(level[i] != -1){
-            printf("%d", level[i]);
-            break;
-        }
-    }
+    auto it = level.begin();
+    printf("%d", it->second);
+    while(++it != level.end()) printf(" %d", it->second);
     return 0;
 }