UVa 1556 Disk Tree

方法： Trie
其实就是建树，node里存文件名。因为最后同目录下的文件要按照文件名顺序输出，所以储存child pointer的时候用了map，自带排序。下面的code是动态分配内存，然而用数组也可以，参见trie template。
Code:
  1 #include <cstdio>
  2 #include <cstring>
  3 #include <algorithm>
  4 #include <iostream>
  5 #include <string>
  6 #include <vector>
  7 #include <stack>
  8 #include <bitset>
  9 #include <cstdlib>
 10 #include <cmath>
 11 #include <set>
 12 #include <list>
 13 #include <deque>
 14 #include <map>
 15 #include <queue>
 16 #include <fstream>
 17 #include <cassert>
 18 #include <unordered_map>
 19 #include <unordered_set>
 20 #include <cmath>
 21 #include <sstream>
 22 #include <time.h>
 23 #include <complex>
 24 #include <iomanip>
 25 #define Max(a,b) ((a)>(b)?(a):(b))
 26 #define Min(a,b) ((a)<(b)?(a):(b))
 27 #define FOR(a,b,c) for (ll (a)=(b);(a)<(c);++(a))
 28 #define FORN(a,b,c) for (ll (a)=(b);(a)<=(c);++(a))
 29 #define DFOR(a,b,c) for (ll (a)=(b);(a)>=(c);--(a))
 30 #define FORSQ(a,b,c) for (ll (a)=(b);(a)*(a)<=(c);++(a))
 31 #define FORC(a,b,c) for (char (a)=(b);(a)<=(c);++(a))
 32 #define FOREACH(a,b) for (auto &(a) : (b))
 33 #define rep(i,n) FOR(i,0,n)
 34 #define repn(i,n) FORN(i,1,n)
 35 #define drep(i,n) DFOR(i,n-1,0)
 36 #define drepn(i,n) DFOR(i,n,1)
 37 #define MAX(a,b) a = Max(a,b)
 38 #define MIN(a,b) a = Min(a,b)
 39 #define SQR(x) ((LL)(x) * (x))
 40 #define Reset(a,b) memset(a,b,sizeof(a))
 41 #define fi first
 42 #define se second
 43 #define mp make_pair
 44 #define pb push_back
 45 #define all(v) v.begin(),v.end()
 46 #define ALLA(arr,sz) arr,arr+sz
 47 #define SIZE(v) (int)v.size()
 48 #define SORT(v) sort(all(v))
 49 #define REVERSE(v) reverse(ALL(v))
 50 #define SORTA(arr,sz) sort(ALLA(arr,sz))
 51 #define REVERSEA(arr,sz) reverse(ALLA(arr,sz))
 52 #define PERMUTE next_permutation
 53 #define TC(t) while(t--)
 54 #define forever for(;;)
 55 #define PINF 1000000000000
 56 #define newline '
'
 57 
 58 #define test if(1)if(0)cerr
 59 using namespace std;
 60 using namespace std;
 61 typedef vector<int> vi;
 62 typedef vector<vi> vvi;
 63 typedef pair<int,int> ii;
 64 typedef pair<double,double> dd;
 65 typedef pair<char,char> cc;
 66 typedef vector<ii> vii;
 67 typedef long long ll;
 68 typedef unsigned long long ull;
 69 typedef pair<ll, ll> l4;
 70 const double pi = acos(-1.0);
 71 
 72 
 73 struct node
 74 {
 75     map<string, node*> child;
 76 };
 77 stack<node*> inuse;
 78 stack<node*> ready;
 79 void clear()
 80 {
 81     while (!inuse.empty())
 82     {
 83         ready.push(inuse.top());
 84         ready.top()->child.clear();
 85         inuse.pop();
 86     }
 87 }
 88 node* new_node()
 89 {
 90     if (ready.empty())
 91     {
 92         node* temp = new node();
 93         ready.push(temp);
 94     }
 95     auto ret = ready.top();
 96     ready.pop();
 97     return ret;
 98 }
 99 int n;
100 node *root;
101 void add(const string &str)
102 {
103     int last = 0;
104     int len = str.length();
105     node *cur = root;
106     for (int i = 0; i <= len; ++i)
107     {
108         if (i == len || str[i] == '\')
109         {
110             string nxt = str.substr(last, i-last);
111             last = i+1;
112             if (cur->child.count(nxt) == 0)
113             {
114                 cur->child[nxt] = new_node();
115             }
116             cur = cur->child[nxt];
117         }
118     }
119 }
120 void print(node* cur, int space)
121 {
122     const string s = string(space, ' ');
123     for (auto &pr : cur->child)
124     {
125         cout << s << pr.first << newline;
126         print(pr.second, space+1);
127     }
128 }
129 int main()
130 {
131     while (cin >> n)
132     {
133         root = new_node();
134         string line;
135         rep(i, n)
136         {
137             cin >> line;
138             add(line);
139         }
140         print(root, 0);
141         clear();
142         cout << newline;
143     }
144     
145 }
146 /*
147  2
148  3 2 cat dog mouse rat bat 1 1 abc cab
149  */
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