#include using namespace std; vector SAIS(vector &A){ //元が数列なら座圧してから. if(A.size() == 1) return {1,0}; for(auto &a : A) a++; A.push_back(0); int siz = A.size(); stack st; vector SL(siz); for(int i=0; i isLMS(siz); vector> LMS(siz2),LMS2(siz2),LMS3(siz2); for(int i=siz-1; i>0; i--){ if(SL.at(i-1) != 1 || SL.at(i) != 0) continue; LMS.at(A.at(i)).push_back(i); isLMS.at(i) = true; } for(int i=0; i=0; i--){ for(int k=0; k=0; k--){ int pos = LMS2.at(i).at(k); if(pos == 0) continue; if(SL.at(pos-1) == 1) continue; LMS3.at(A.at(pos-1)).push_back(pos-1); } } vector check,Next(siz); for(int i=0; i=0; k--){ int &a = LMS3.at(i).at(k); if(isLMS.at(a)) check.push_back(a); } } int siz3 = check.size(); bool More = false; for(int i=0; i Take,Give,Rev; for(int i=0; i=0; i--){ for(int k=0; k=0; k--){ int pos = LMS2.at(i).at(k); if(pos == 0) continue; if(SL.at(pos-1) == 1) continue; LMS3.at(A.at(pos-1)).push_back(pos-1); } } vector check2; for(int i=0; i=0; k--){ int &a = LMS3.at(i).at(k); check2.push_back(a); } } A.pop_back(); for(auto &a : A) a--; return check2; } void to_int(string &s,vector &A){for(char c : s) A.push_back(c);} vector LCP(vector &SA,vector &A){ A.push_back(-1); int siz = SA.size(); vector Look(siz); for(int i=0; i ret(siz-1); for(int i=0; i dat; SS op(SS a, SS b){return min(a,b);} SS e(){return 1001001001;} void renew (SS &a,SS x){ a = op(a,x); //a = x; //set(pos,x)で可能. //その他. } SegmentTree(int N){init(N);} SegmentTree(const vector &A){//長さ配列サイズに合わせる. siz = 1; n = A.size(); while(siz < n) siz *= 2; dat.resize(siz*2,e()); for(int i=0; i0; i--) dat.at(i) = op(dat.at(i*2),dat.at(i*2+1)); } void init(int N){ //全要素単位元に初期化. siz = 1; n = N; while(siz < n) siz *= 2; dat.assign(siz*2,e()); } void init(const vector &A){//長さ配列サイズに合わせる. siz = 1; n = A.size(); while(siz < n) siz *= 2; dat.resize(siz*2,e()); for(int i=0; i0; i--) dat.at(i) = op(dat.at(i*2),dat.at(i*2+1)); } void set(int pos,SS x){ pos = pos+siz; dat.at(pos) = x; while(pos != 1){ pos = pos/2; dat.at(pos) = op(dat.at(pos*2),dat.at(pos*2+1)); } } void update(int pos,SS x){ pos = pos+siz; renew(dat.at(pos),x); while(pos != 1){ pos = pos/2; dat.at(pos) = op(dat.at(pos*2),dat.at(pos*2+1)); } } SS findans(int l, int r){ SS retl = e(),retr = e(); l += siz,r += siz; while(l < r){ if(l&1) retl = op(retl,dat.at(l++)); if(r&1) retr = op(dat.at(--r),retr); l >>= 1; r >>= 1; } return op(retl,retr); } SS get(int pos){return dat.at(pos+siz);} SS rangeans(int l, int r){return findans(l,r);} SS allrange(){return dat.at(1);} //rightは) leftは[で 渡す&返す. int maxright(const function f,int l = 0){ //fを満たさない最小の箇所を返す なければn. l += siz; int r = n+siz; vector ls,rs; while(l < r){ if(l&1) ls.push_back(l++); if(r&1) rs.push_back(--r); l >>= 1; r >>= 1; } SS okl = e(); for(int i=0; i=0; i--){ l = rs.at(i); SS now = op(okl,dat.at(l)); if(!f(now)){ while(l < siz){ l <<= 1; now = op(okl,dat.at(l)); if(f(now)){okl = now; l++;} } return l-siz; } okl = now; } return n; } int minleft(const function f,int r = -1){ //fを満たす最小の箇所を返す なければ0. if(r == -1) r = n; int l = siz; r += siz; vector ls,rs; while(l < r){ if(l&1) ls.push_back(l++); if(r&1) rs.push_back(--r); l >>= 1; r >>= 1; } SS okr = e(); for(int i=0; i=0; i--){ r = ls.at(i); SS now = op(dat.at(r),okr); if(!f(now)){ while(r < siz){ r <<= 1; r++; now = op(dat.at(r),okr); if(f(now)){okr = now; r--;} } return r+1-siz; } okr = now; } return 0; } }; class SegmentTree2{ public: int siz = -1,n = -1; vector dat; SS op(SS a, SS b){return a+b;} SS e(){return 0;} void renew (SS &a,SS x){ a = op(a,x); //a = x; //set(pos,x)で可能. //その他. } SegmentTree2(int N){init(N);} SegmentTree2(const vector &A){//長さ配列サイズに合わせる. siz = 1; n = A.size(); while(siz < n) siz *= 2; dat.resize(siz*2,e()); for(int i=0; i0; i--) dat.at(i) = op(dat.at(i*2),dat.at(i*2+1)); } void init(int N){ //全要素単位元に初期化. siz = 1; n = N; while(siz < n) siz *= 2; dat.assign(siz*2,e()); } void init(const vector &A){//長さ配列サイズに合わせる. siz = 1; n = A.size(); while(siz < n) siz *= 2; dat.resize(siz*2,e()); for(int i=0; i0; i--) dat.at(i) = op(dat.at(i*2),dat.at(i*2+1)); } void set(int pos,SS x){ pos = pos+siz; dat.at(pos) = x; while(pos != 1){ pos = pos/2; dat.at(pos) = op(dat.at(pos*2),dat.at(pos*2+1)); } } void update(int pos,SS x){ pos = pos+siz; renew(dat.at(pos),x); while(pos != 1){ pos = pos/2; dat.at(pos) = op(dat.at(pos*2),dat.at(pos*2+1)); } } SS findans(int l, int r){ SS retl = e(),retr = e(); l += siz,r += siz; while(l < r){ if(l&1) retl = op(retl,dat.at(l++)); if(r&1) retr = op(dat.at(--r),retr); l >>= 1; r >>= 1; } return op(retl,retr); } SS get(int pos){return dat.at(pos+siz);} SS rangeans(int l, int r){return findans(l,r);} SS allrange(){return dat.at(1);} //rightは) leftは[で 渡す&返す. int maxright(const function f,int l = 0){ //fを満たさない最小の箇所を返す なければn. l += siz; int r = n+siz; vector ls,rs; while(l < r){ if(l&1) ls.push_back(l++); if(r&1) rs.push_back(--r); l >>= 1; r >>= 1; } SS okl = e(); for(int i=0; i=0; i--){ l = rs.at(i); SS now = op(okl,dat.at(l)); if(!f(now)){ while(l < siz){ l <<= 1; now = op(okl,dat.at(l)); if(f(now)){okl = now; l++;} } return l-siz; } okl = now; } return n; } int minleft(const function f,int r = -1){ //fを満たす最小の箇所を返す なければ0. if(r == -1) r = n; int l = siz; r += siz; vector ls,rs; while(l < r){ if(l&1) ls.push_back(l++); if(r&1) rs.push_back(--r); l >>= 1; r >>= 1; } SS okr = e(); for(int i=0; i=0; i--){ r = ls.at(i); SS now = op(dat.at(r),okr); if(!f(now)){ while(r < siz){ r <<= 1; r++; now = op(dat.at(r),okr); if(f(now)){okr = now; r--;} } return r+1-siz; } okr = now; } return 0; } }; int main(){ ios_base::sync_with_stdio(false); cin.tie(nullptr); int T; cin >> T; while(T--){ long long N,K; cin >> N >> K; vector A(N); for(auto &a : A) cin >> a,a--; auto S = SAIS(A); auto L = LCP(S,A); L.push_back(0); int border = 1; auto f = [&](SS x) -> bool {return x>=border;}; stack> st; st.push({0,N+1000}); SegmentTree Z(L); SegmentTree2 Z2(S); bool end = false; for(int i=1; i<=N; i++){ int l = L.at(i),r = Z.maxright(f,i)+1; long long sum = Z2.rangeans(i,r); sum = (r-i)*(N+1-border)-sum; if(sum < K){i = r-1,K -= sum; continue;} K -= r-i; if(K <= 0){ for(int p=S.at(i); p