Submission #979143

#TimeUsernameProblemLanguageResultExecution timeMemory
979143canadavid1송신탑 (IOI22_towers)C++17
0 / 100
451 ms2612 KiB
#include "towers.h" #include <vector> #include <numeric> #include <algorithm> #include <set> struct SegmentTree { private: std::vector<int> data; struct SegTreeReference { private: const int pos; SegmentTree& t; public: SegTreeReference(int pos,SegmentTree& t) : pos(pos), t(t) {} int operator=(int val) { t.assign(pos,val); return val; } operator int() const {return t.data[t.data.size()/2+pos];} }; public: SegmentTree() : data(0) {} SegmentTree(int num) : data(num*2,0) {} SegmentTree(const std::vector<int>& vec) : data(vec.size()*2) { for(int i = 0; i < vec.size(); i++) data[vec.size()+i] = vec[i]; for(int i = vec.size()-1; i > 0; i--) data[i] = std::max(data[2*i],data[2*i+1]); } void assign(int pos, int val) { data[pos] = val; pos >>= 1; for(;pos>0;pos>>=1) data[pos] = std::max(data[2*pos],data[2*pos+1]); } SegTreeReference operator[](int pos) { return SegTreeReference(pos,*this); } int query(int l, int r) { l += data.size()/2; r += data.size()/2; int o = -(1<<31); while(l < r) { if(l&1) o = std::max(o,data[l++]); if(r&1) o = std::max(o,data[--r]); l>>=1; r>>=1; } return o; } void push_back(int v) { int N = data.size()/2; data.push_back(data[N]); data.push_back(v); data[N] = std::max(data[2*N],data[2*N+1]); } }; std::vector<int> H; std::vector<int> rep; SegmentTree st; void init(int N, std::vector<int> _H) { H = std::move(_H); rep.resize(H.size()); int p=0; for(int i = 0; i < rep.size(); i++) { if(H[p]==H[i]) rep[i] = p; else { p = i; rep[i] = i; } } std::vector<int> minima(H.size()); for(int i = 1; i < H.size()-1;i++) minima[i] = H[i-1] > H[i] && H[i] <= H[i+1]; // annoying if range is 2I1(1112I1) // WLOG take the leftmost in an equal range st = decltype(st)(minima); } int max_towers(int L, int R, int D) { L = rep[L]; // take entire range auto a = st.query(L,R+1); if(!st.query(R,R+1) && H[R-1] > H[R]) a++; if(!st.query(L,L+1) && H[L-1] > H[L]) a++; return a; } /* WLOG all leased towers are local minima or endpoints DONE s1: "concave": lease extrema if possible DONE s2: N <= 1000, Q=1: choose towers from smallest to largest DONE s23: Q = 1 s4: D = 1 take any which is a local minima s46: D fixed -> scheduling problem (each tower excludes a certain area) constrained: won't have ([)] - matched parens whichever is taller is the outer paren tree of ranges s5: L,R is entire range WLOG use smallest tower use next smallest that works need to quickly check if it works (logn time) or not (subtask 2) repeat */

Compilation message (stderr)

towers.cpp: In constructor 'SegmentTree::SegmentTree(const std::vector<int>&)':
towers.cpp:31:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   31 |         for(int i = 0; i < vec.size(); i++) data[vec.size()+i] = vec[i];
      |                        ~~^~~~~~~~~~~~
towers.cpp: In member function 'int SegmentTree::query(int, int)':
towers.cpp:51:17: warning: integer overflow in expression of type 'int' results in '-2147483648' [-Woverflow]
   51 |         int o = -(1<<31);
      |                 ^~~~~~~~
towers.cpp: In function 'void init(int, std::vector<int>)':
towers.cpp:78:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |     for(int i = 0; i < rep.size(); i++)
      |                    ~~^~~~~~~~~~~~
towers.cpp:89:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |     for(int i = 1; i < H.size()-1;i++)
      |                    ~~^~~~~~~~~~~~
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...
#Verdict Execution timeMemoryGrader output
Fetching results...