【HDOJ】2890 Longest Repeated subsequence

后缀数组的应用。和男人八题那个后缀数组差不多。

 /* 2890 */
 #include <iostream>
 #include <sstream>
 #include <string>
 #include <map>
 #include <queue>
 #include <set>
 #include <stack>
 #include <vector>
 #include <deque>
 #include <algorithm>
 #include <cstdio>
 #include <cmath>
 #include <ctime>
 #include <cstring>
 #include <climits>
 #include <cctype>
 #include <cassert>
 #include <functional>
 #include <iterator>
 #include <iomanip>
 using namespace std;
 //#pragma comment(linker,"/STACK:102400000,1024000")

 #define sti                set<int>
 #define stpii            set<pair<int, int> >
 #define mpii            map<int,int>
 #define vi                vector<int>
 #define pii                pair<int,int>
 #define vpii            vector<pair<int,int> >
 #define rep(i, a, n)     for (int i=a;i<n;++i)
 #define per(i, a, n)     for (int i=n-1;i>=a;--i)
 #define clr                clear
 #define pb                 push_back
 #define mp                 make_pair
 #define fir                first
 #define sec                second
 #define all(x)             (x).begin(),(x).end()
 #define SZ(x)             ((int)(x).size())
 #define lson            l, mid, rt<<1
 #define rson            mid+1, r, rt<<1|1

 const int maxn = ;
 int a[maxn], b[maxn], aa[maxn];
 int pos[maxn], pn;
 int rrank[maxn], height[maxn], sa[maxn];
 int wa[maxn], wb[maxn], wc[maxn], wv[maxn];
 int n, k, at;

 bool cmp(int *r, int a, int b, int l) {
     return r[a]==r[b] && r[a+l]==r[b+l];
 }

 void da(int *r, int *sa, int n, int m) {
     int i, j, *x=wa, *y=wb, *t, p;

     for (i=; i<m; ++i) wc[i] = ;
     for (i=; i<n; ++i) wc[x[i]=r[i]]++;
     for (i=; i<m; ++i) wc[i] += wc[i-];
     for (i=n-; i>=; --i) sa[--wc[x[i]]] = i;
     for (j=,p=; p<n; j*=, m=p) {
         for (p=,i=n-j; i<n; ++i) y[p++] = i;
         for (i=; i<n; ++i) if (sa[i] >= j) y[p++] = sa[i] - j;
         for (i=; i<n; ++i) wv[i] = x[y[i]];
         for (i=; i<m; ++i) wc[i] = ;
         for (i=; i<n; ++i) wc[wv[i]]++;
         for (i=; i<m; ++i) wc[i] += wc[i-];
         for (i=n-; i>=; --i) sa[--wc[wv[i]]] = y[i];
         for (t=x, x=y, y=t, i=,p=,x[sa[]]=; i<n; ++i)
             x[sa[i]] = cmp(y, sa[i-], sa[i], j) ? p-:p++;
     }
 }

 void calheight(int *r, int *sa, int n) {
     int i, j, k=;

     for (i=; i<=n; ++i) rrank[sa[i]] = i;
     for (i=; i<n; height[rrank[i++]]=k)
     for (k?k--:, j=sa[rrank[i]-]; r[i+k]==r[j+k]; ++k);
 }

 bool judge(int bound) {
     int i = ;
     int pn = ;

     while (i <= n) {
         if (height[i] < bound) {
             at = sa[i-];
             sort(pos, pos+pn);
             int kk = , p = pos[];
             rep(j, , pn) {
                 if (pos[j]-p >= bound) {
                     p = pos[j];
                     ++kk;
                 }
             }

             if (kk >= k)
                 return true;
             pn = ;
             pos[pn++] = sa[i++];
         } else {
             pos[pn++] = sa[i++];
         }
     }
     at = sa[n-];
     sort(pos, pos+pn);
     int kk = , p = pos[];
     rep(j, , pn) {
         if (pos[j]-p >= bound) {
             p = pos[j];
             ++kk;
         }
     }

     if (kk >= k)
         return true;

     return false;
 }

 void printSa(int n) {
     for (int i=; i<=n; ++i)
         printf("%d ", sa[i]);
     putchar('\n');
 }

 void printHeight(int n) {
     for (int i=; i<=n; ++i)
         printf("%d ", height[i]);
     putchar('\n');
 }

 void solve() {
     sort(b, b+n);
     int nn = unique(b, b+n) - b;

     rep(i, , n)
         aa[i] = lower_bound(b, b+nn, a[i]) - b + ;
     aa[n] = ;

     da(aa, sa, n+, nn+);
     calheight(aa, sa, n);

     #ifndef ONLINE_JUDGE
         // printSa(n);
         // printHeight(n);
     #endif

     int l = , r = n, mid;
     int ans = , fr;

     while (l <= r) {
         mid = (l + r) >> ;
         if (judge(mid)) {
             ans = mid;
             fr = at;
             l = mid + ;
         } else {
             r = mid - ;
         }
     }

     printf("%d\n", ans);
     rep(i, , ans)
         printf("%d\n", b[aa[fr+i]-]);
 }

 int main() {
     ios::sync_with_stdio(false);
     #ifndef ONLINE_JUDGE
         freopen("data.in", "r", stdin);
         freopen("data.out", "w", stdout);
     #endif

     int t;

     scanf("%d", &t);
     while (t--) {
         scanf("%d %d", &n, &k);
         rep(i, , n) {
             scanf("%d", &a[i]);
             b[i] = a[i];
         }
         solve();
         if (t)
             putchar('\n');
     }

     #ifndef ONLINE_JUDGE
         printf("time = %d.\n", (int)clock());
     #endif

     return ;
 }