HDOJ4691 Front compression

Posted 2020-06-13

后缀数组基础题目，dc3解。

  1 /* 4691 */
  2 #include <iostream>
  3 #include <sstream>
  4 #include <string>
  5 #include <map>
  6 #include <queue>
  7 #include <set>
  8 #include <stack>
  9 #include <vector>
 10 #include <deque>
 11 #include <algorithm>
 12 #include <cstdio>
 13 #include <cmath>
 14 #include <ctime>
 15 #include <cstring>
 16 #include <climits>
 17 #include <cctype>
 18 #include <cassert>
 19 #include <functional>
 20 #include <iterator>
 21 #include <iomanip>
 22 using namespace std;
 23 //#pragma comment(linker,"/STACK:102400000,1024000")
 24 
 25 #define sti                set<int>
 26 #define stpii            set<pair<int, int> >
 27 #define mpii            map<int,int>
 28 #define vi                vector<int>
 29 #define pii                pair<int,int>
 30 #define vpii            vector<pair<int,int> >
 31 #define rep(i, a, n)     for (int i=a;i<n;++i)
 32 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 33 #define clr                clear
 34 #define pb                 push_back
 35 #define mp                 make_pair
 36 #define fir                first
 37 #define sec                second
 38 #define all(x)             (x).begin(),(x).end()
 39 #define SZ(x)             ((int)(x).size())
 40 #define lson            l, mid, rt<<1
 41 #define rson            mid+1, r, rt<<1|1
 42 
 43 const int INF = 0x3f3f3f3f;
 44 const int maxl = 1e5+5;
 45 const int maxn = 1e5+5;
 46 char s[maxl];
 47 int nw;
 48 int A[maxn], B[maxn];
 49 int a[maxn*3];
 50 int height[maxn], rrank[maxn], sa[maxn*3];
 51 int wa[maxn], wb[maxn], wc[maxn], wv[maxn];
 52 int dp[maxn][17];
 53 
 54 bool c0(int *r, int a, int b) {
 55     return r[a]==r[b] && r[a+1]==r[b+1] && r[a+2]==r[b+2];
 56 }
 57 
 58 bool c12(int k, int *r, int a, int b) {
 59     if (k == 2)
 60         return r[a]<r[b] || (r[a]==r[b] && c12(1, r, a+1, b+1));
 61     else
 62         return r[a]<r[b] || (r[a]==r[b] && wv[a+1]<wv[b+1]);
 63 }
 64 
 65 void sort(int *r, int *a, int *b, int n, int m) {
 66     int i;
 67     
 68     for (i=0; i<n; ++i) wv[i] = r[a[i]];
 69     for (i=0; i<m; ++i) wc[i] = 0;
 70     for (i=0; i<n; ++i) wc[wv[i]]++;
 71     for (i=1; i<m; ++i) wc[i] += wc[i-1];
 72     for (i=n-1; i>=0; --i) b[--wc[wv[i]]] = a[i];
 73 }
 74 
 75 #define F(x) ((x)/3 + ((x)%3==1 ? 0:tb))
 76 #define G(x) ((x)<tb ? (x)*3+1 : ((x)-tb)*3+2)
 77 void dc3(int *r, int *sa, int n, int m) {
 78     int i, j, *rn=r+n, *san=sa+n, ta=0, tb=(n+1)/3, tbc=0, p;
 79     
 80     r[n] = r[n+1] = 0;
 81     for (i=0; i<n; ++i) if (i%3!=0) wa[tbc++] = i;
 82     sort(r+2, wa, wb, tbc, m);
 83     sort(r+1, wb, wa, tbc, m);
 84     sort(r, wa, wb, tbc, m);
 85     for (p=1, rn[F(wb[0])]=0, i=1; i<tbc; ++i)
 86         rn[F(wb[i])] = c0(r, wb[i-1], wb[i]) ? p-1:p++;
 87     if (p < tbc)
 88         dc3(rn, san, tbc, p);
 89     else
 90         for (i=0; i<tbc; ++i) san[rn[i]] = i;
 91     for (i=0; i<tbc; ++i)
 92         if (san[i] < tb)
 93             wb[ta++] = san[i] * 3;
 94     if (n%3 == 1)
 95         wb[ta++] = n - 1;
 96     sort(r, wb, wa, ta, m);
 97     for (i=0; i<tbc; ++i) wv[wb[i]=G(san[i])] = i;
 98     for (i=0,j=0,p=0; i<ta && j<tbc; ++p)
 99         sa[p] = c12(wb[j]%3, r, wa[i], wb[j]) ? wa[i++] : wb[j++];
100     while (i < ta) sa[p++] = wa[i++];
101     while (j < tbc) sa[p++] = wb[j++];
102 }
103 
104 void calheight(int *r, int *sa, int n) {
105     int i, j, k = 0;
106     
107     for (i=1; i<=n; ++i) rrank[sa[i]] = i;
108     for (i=0; i<n; height[rrank[i++]]=k)
109     for (k?k--:0, j=sa[rrank[i]-1]; r[j+k]==r[i+k]; ++k) ;
110 }
111 
112 void init_RMQ(int n) {
113     int i, j;
114     
115     for (i=1; i<=n; ++i)
116         dp[i][0] = height[i];
117     dp[1][0] = INF;
118     for (j=1; (1<<j)<=n; ++j)
119         for (i=1; i+(1<<j)-1<=n; ++i)
120             dp[i][j] = min(dp[i][j-1], dp[i+(1<<(j-1))][j-1]);
121 }
122 
123 int RMQ(int l, int r) {
124     if (l > r)
125         swap(l, r);
126     
127     ++l;
128     int k = 0;
129     
130     while (1<<(k+1) <= r-l+1)
131         ++k;
132     
133     return min(dp[l][k], dp[r-(1<<k)+1][k]);
134 }
135 
136 void printSa(int n) {
137     for (int i=1; i<=n; ++i)
138         printf("%d ", sa[i]);
139     putchar(‘\n‘);
140 }
141 
142 void printRank(int n) {
143     for (int i=1; i<=n; ++i)
144         printf("%d ", rrank[i]);
145     putchar(‘\n‘);
146 }
147 
148 void printHeight(int n) {
149     for (int i=1; i<=n; ++i)
150         printf("%d ", height[i]);
151     putchar(‘\n‘);
152 }
153 
154 int getBit(int x) {
155     if (x == 0)
156         return 1;
157     
158     int ret = 0;
159     
160     while (x) {
161         ++ret;
162         x /= 10;
163     }
164     
165     return ret;
166 }
167 
168 void solve() {
169     int n = 0;
170     
171     for (int i=0; ; ++i) {
172         if (s[i] == ‘\0‘) {
173             n = i;
174             break;
175         }
176         a[i] = s[i] - ‘a‘ + 1;
177     }
178     a[n] = 0;
179     
180     dc3(a, sa, n+1, 30);
181     calheight(a, sa, n);
182     
183     #ifndef ONLINE_JUDGE
184         // printSa(n);
185         // printRank(n);
186         // printHeight(n);
187     #endif
188     
189     init_RMQ(n);
190     
191     __int64 ansa, ansb;
192     int pl, l, mnl, tmp;
193     
194     pl = B[0] - A[0];
195     ansa = pl;
196     ansb = pl + 2;
197     
198     rep(i, 1, nw) {
199         l = B[i] - A[i];
200         mnl = min(l, pl);
201         if (A[i] == A[i-1]) {
202             tmp = mnl;
203         } else {
204             tmp = RMQ(rrank[A[i-1]], rrank[A[i]]);
205             if (tmp > mnl)
206                 tmp = mnl;
207         }
208         #ifndef ONLINE_JUDGE
209             // printf("%d: tmp = %d\n", i, tmp);
210         #endif
211         ansa += l;
212         ansb += getBit(tmp) + 1 + l - tmp;
213         pl = l;
214     }
215     
216     ansa += nw;
217     ansb += nw;
218     
219     printf("%I64d %I64d\n", ansa, ansb);
220 }
221 
222 int main() {
223     ios::sync_with_stdio(false);
224     #ifndef ONLINE_JUDGE
225         freopen("data.in", "r", stdin);
226         freopen("data.out", "w", stdout);
227     #endif
228     
229     while (scanf("%s", s) != EOF) {
230         scanf("%d", &nw);
231         rep(i, 0, nw)
232             scanf("%d %d", &A[i], &B[i]);
233         solve();
234     }
235     
236     #ifndef ONLINE_JUDGE
237         printf("time = %d.\n", (int)clock());
238     #endif
239     
240     return 0;
241 }

数据生成器。

 1 from random import randint, shuffle
 2 import shutil
 3 import string
 4 
 5 
 6 def GenDataIn():
 7     with open("data.in", "w") as fout:
 8         t = 20
 9         bound = 10**3
10         lc = list(string.lowercase)
11         for tt in xrange(t):
12             length = randint(50, 105)
13             line = ""
14             for i in xrange(length):
15                 idx = randint(0, 10)
16                 line += lc[idx]
17             fout.write("%s\n" % (line))
18             n = randint(1, 20)
19             fout.write("%d\n" % (n))
20             for i in xrange(n):
21                 a = randint(0, length-1)
22                 b = randint(a+1, length)
23                 fout.write("%d %d\n" % (a, b))
24         
25                 
26 def MovDataIn():
27     desFileName = "F:\eclipse_prj\workspace\hdoj\data.in"
28     shutil.copyfile("data.in", desFileName)
29 
30     
31 if __name__ == "__main__":
32     GenDataIn()
33     MovDataIn()