UVa 11732 - strcmp() Anyone? (Trie + 邻接表)

思路

为了节省空间，用了邻接表。

记录一下在每个节点是否有单词结束，

然后边插入边比较

参考了ShoutMoon的代码

代码

  
  
  
  

   
   
   
   
#include <cstdio>
   
   
   
   
#include <stack>
   
   
   
   
#include <set>
   
   
   
   
#include <iostream>
   
   
   
   
#include <string>
   
   
   
   
#include <vector>
   
   
   
   
#include <queue>
   
   
   
   
#include <functional>
   
   
   
   
#include <cstring>
   
   
   
   
#include <algorithm>
   
   
   
   
#include <cctype>
   
   
   
   
#include <ctime>
   
   
   
   
#include <cstdlib>
   
   
   
   
#include <fstream>
   
   
   
   
#include <string>
   
   
   
   
#include <sstream>
   
   
   
   
#include <map>
   
   
   
   
#include <cmath>
   
   
   
   
#define LL long long
   
   
   
   
#define SZ(x) (int)x.size()
   
   
   
   
#define Lowbit(x) ((x) & (-x))
   
   
   
   
#define MP(a, b) make_pair(a, b)
   
   
   
   
#define MS(arr, num) memset(arr, num, sizeof(arr))
   
   
   
   
#define PB push_back
   
   
   
   
#define F first
   
   
   
   
#define S second
   
   
   
   
#define ROP freopen("input.txt", "r", stdin);
   
   
   
   
#define MID(a, b) (a + ((b - a) >> 1))
   
   
   
   
#define LC rt << 1, l, mid
   
   
   
   
#define RC rt << 1|1, mid + 1, r
   
   
   
   
#define LRT rt << 1
   
   
   
   
#define RRT rt << 1|1
   
   
   
   
#define BitCount(x) __builtin_popcount(x)
   
   
   
   
const double PI = acos(-1.0);
   
   
   
   
const int INF = 0x3f3f3f3f;
   
   
   
   
using namespace std;
   
   
   
   
const int MAXN = 4000 * 1000 + 5;
   
   
   
   
const int MOD = 20071027;
   
   
   
   

   
   
   
   
typedef pair<int, int> pii;
   
   
   
   
typedef vector<int>::iterator viti;
   
   
   
   
typedef vector<pii>::iterator vitii;
   
   
   
   

   
   
   
   
char str[1010];
   
   
   
   

   
   
   
   
struct TRIE
   
   
   
   
{
   
   
   
   
 int head[MAXN], next[MAXN], ch[MAXN], val[MAXN];
   
   
   
   
 int sz;
   
   
   
   
 LL ans;
   
   
   
   

   
   
   
   
 void init()
   
   
   
   
 {
   
   
   
   
 sz = 1; ans = 0; ch[0] = 0; head[0] = next[0] = val[0] = 0;
   
   
   
   
 }
   
   
   
   

   
   
   
   
 void insert(char *s)
   
   
   
   
 {
   
   
   
   
 int len = strlen(s), u = 0, p;
   
   
   
   
 for (int i = 0; i <= len; i++)
   
   
   
   
 {
   
   
   
   
 for (p = head[u]; p; p = next[p])
   
   
   
   
 if (ch[p] == s[i]) break;
   
   
   
   
 if (!p)
   
   
   
   
 {
   
   
   
   
 p = sz++;
   
   
   
   
 ch[p] = s[i];
   
   
   
   
 next[p] = head[u];
   
   
   
   
 head[u] = p;
   
   
   
   
 head[p] = 0;
   
   
   
   
 val[p] = 0;
   
   
   
   
 }
   
   
   
   
 ans += (val[u] - val[p]) * (2 * i + 1);
   
   
   
   
 if (i == len)
   
   
   
   
 {
   
   
   
   
 ans += val[p] * (2 * (i + 1));
   
   
   
   
 val[p]++;
   
   
   
   
 }
   
   
   
   
 val[u]++;
   
   
   
   
 u = p;
   
   
   
   
 }
   
   
   
   
 }
   
   
   
   

   
   
   
   
}trie;
   
   
   
   

   
   
   
   
int main()
   
   
   
   
{
   
   
   
   
 //ROP;
   
   
   
   
 int n, i, j, cases = 0;
   
   
   
   
 while (scanf("%d%*c", &n), n)
   
   
   
   
 {
   
   
   
   
 trie.init();
   
   
   
   
 while (n--)
   
   
   
   
 {
   
   
   
   
 scanf("%s", str);
   
   
   
   
 trie.insert(str);
   
   
   
   
 }
   
   
   
   
 printf("Case %d: %lld\n", ++cases, trie.ans);
   
   
   
   
 }
   
   
   
   
 return 0;
   
   
   
   
}