AC 127, 运行时间有点慢

Author: eytter48

P127.cpp

@@ -0,0 +1,86 @@
+#include "header.h"
+#include <array>
+#include <bits/c++config.h>
+#include <cstddef>
+#include <cstring>
+#include <vector>
+
+
+#define LEN 5001
+class Solution {
+public:
+    int ladderLength(string beginWord, string endWord, vector<string>& wordList) {
+        array<bool, LEN> end;
+        array<bool, LEN> visited;
+        visited.fill(false);
+        bool begin;
+        bool hasEnd = false;
+        end.fill(false);
+        queue<pair<int, int>> q;
+        for (size_t i=0; i<wordList.size(); i++) {
+            if (transfer(beginWord, wordList[i])) begin = true;
+            else begin=false;
+            if (transfer(endWord, wordList[i])) end[i] = true;
+            if (endWord == wordList[i]) hasEnd = true;
+            if (begin) {
+                q.emplace(i,2);
+                visited[i] = true;
+            }
+        }
+        if (!hasEnd) return 0;
+        if (transfer(beginWord, endWord)) return 2;
+        const size_t &n = wordList.size();
+        static int map[LEN][LEN];
+        for (size_t i=0; i<n; i++) 
+            map[i][0] = 0;
+        for (size_t i=0; i<n; i++) {
+            for (size_t j=i+1; j<n; j++) {
+                if (transfer(wordList[i], wordList[j])) {
+                    map[i][++map[i][0]] = j;
+                    map[j][++map[j][0]] = i;
+                }
+            }
+        }
+        
+        while (!q.empty()) {
+            int _last = q.front().first;
+            int _step = q.front().second;
+            if (end[_last]) {
+                return _step+1;
+            }
+
+            for (int i=1; i<=map[_last][0]; i++) {
+                int j = map[_last][i];
+                if (!visited[j]) {
+                    q.emplace(j, _step+1);
+                    visited[j] = true;
+                }
+            }
+            q.pop();
+        }
+        return 0;
+    }
+private:
+    bool transfer(const string &a,const string &b) {
+        int differ = 0;
+        if (a.size()!=b.size()) return false;
+        for (size_t i=0; i<a.size(); i++)
+            if (a[i]!=b[i]) {
+                differ++;
+                if (differ>1) return false;
+            }
+        if (differ==1) 
+            return true;
+        else 
+            return false;
+    }
+};
+
+int main() {
+    string beginWord = "a";
+    string endWord = "c";
+    vector<string> wordList = {"a", "b", "c"};
+    cout << Solution().ladderLength(beginWord, endWord, wordList) << endl;
+
+    return 0;
+}

header.h

@@ -1,4 +1,5 @@
 #include <array>
+#include <bits/c++config.h>
 #include <cstdint>
 #include<iostream>
 #include<vector>
@@ -76,3 +77,11 @@ void print(vector<T> a) {
     cout << endl;
     return;
 }
+
+template<typename T>
+void print(T a[], size_t n) {
+    for (size_t i=0; i<n; i++) 
+        cout << a[i] << " ";
+    cout << endl;
+    return;
+}