Submission #797161

#	Time	Username	Problem	Language	Result	Execution time	Memory
797161		Sam_a17	Election (BOI18_election)	C++17	0 / 100	3 ms	340 KiB

election

#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
// #include <atcoder/all>
#include <cstdio>
using namespace std;
 
#ifndef ONLINE_JUDGE
#define dbg(x) cerr << #x <<" "; print(x); cerr << endl;
#else
#define dbg(x)
#endif
 
#define sz(x) (int((x).size()))
#define len(x) (int)x.length()
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define blt(x) __builtin_popcount(x)
#define uniq(x) x.resize(unique(all(x)) - x.begin());
 
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ld long double
#define ll long long
 
void print(long long t) {cerr << t;}
void print(int t) {cerr << t;}
void print(string t) {cerr << t;}
void print(char t) {cerr << t;}
void print(double t) {cerr << t;}
void print(unsigned long long t) {cerr << t;}
void print(long double t) {cerr << t;}
 
template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T> void print(T v[],T n) {cerr << "["; for(int i = 0; i < n; i++) {cerr << v[i] << " ";} cerr << "]";}
template <class T, class V> void print(pair <T, V> p) {cerr << "{"; print(p.first); cerr << ","; print(p.second); cerr << "}";}
template <class T> void print(vector <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(deque <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(set <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T> void print(multiset <T> v) {cerr << "[ "; for (T i : v) {print(i); cerr << " ";} cerr << "]";}
template <class T, class V> void print(map <T, V> v) {cerr << "[ "; for (auto i : v) {print(i); cerr << " ";} cerr << "]";}
 
#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;
#define nl '\n'
 
// for random generations
mt19937 myrand(chrono::steady_clock::now().time_since_epoch().count());
// mt19937 myrand(131);
 
// for grid problems
int dx[8] = {1,0,-1,0,1,-1,1,-1};
int dy[8] = {0,1,0,-1,1,1,-1,-1};
char ch[4] = {'v', '>', '^', '<'};
 
long long ka() {
    long long x = 0;
    bool z = false;
    while (1)
    {
        char y = getchar();
        if (y == '-')
            z = true;
        else if ('0' <= y && y <= '9')
            x = x * 10 + y - '0';
        else
        {
            if (z)
                x *= -1;
            return x;
        }
    }
}
 
// lowest / (1 << 17) >= 1e5 / (1 << 18) >= 2e5 / (1 << 21) >= 1e6
void fastIO() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr); cout.tie(nullptr);
}
// file in/out
void setIO(string str = "") {
  fastIO();
 
  if (str != "") {
    freopen((str + ".in").c_str(), "r", stdin);
    freopen((str + ".out").c_str(), "w", stdout);
  } else if(str == "input") {
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
  }
}
 
// Indexed Set
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

struct segTreeMin {
  vector<long long> mTree;
  int size;
 
  void init(long long n) {
    size = 1;
    while(size < n)  {
      size *= 2;
    }
    mTree.assign(2 * size - 1, 0);
  }
 
  void upd(int u, long long v, int x, int lx, int rx) { // set value at pos u
    if(rx - lx == 1) {
      mTree[x] = v;
      return;
    }
 
    int m = (lx + rx) / 2;
    if(u < m) {
      upd(u, v, 2 * x + 1, lx, m);
    }else {
      upd(u, v, 2 * x + 2, m, rx);
    }
    mTree[x] = min(mTree[2 * x + 1], mTree[2 * x + 2]);
  }
 
  void upd(int u, long long v) {
    upd(u, v, 0, 0, size);
  }
 
  long long qry (int l, int r, int x, int lx, int rx) { // range queries
    if(l >= rx || lx >= r) {
      return INT32_MAX;
    }

    if(lx >= l && r >= rx) {
      return mTree[x];
    }
 
    int m = (rx + lx) / 2;
    long long s1 = qry(l, r, 2 * x + 1, lx, m);
    long long s2 = qry(l, r, 2 * x + 2, m, rx);
    return min(s1, s2);
  }
 
  long long qry(int l, int r) {
    return qry(l, r, 0, 0, size);
  }
};

segTreeMin seg_p, seg_s;

const int N = 5e5 + 10;
char s[N];

void solve_() {
  int n; cin >> n;
  
  int p = 0;
  vector<int> pref(n + 1), indices;
  map<int, vector<int>> mp;
  mp[0].push_back(0);

  seg_p.init(n + 1);
  seg_s.init(n + 1);
  for(int i = 1; i <= n; i++) {
    cin >> s[i];

    if(s[i] == 'T') p--, indices.push_back(i);
    else p++;
    seg_p.upd(i, p);
    mp[p].push_back(i);

    pref[i] = pref[i - 1] + (s[i] == 'C'); 
  }
  int q; cin >> q;

  p = 0;
  for(int i = n; i >= 1; i--) {
    if(s[i] == 'T') p--;
    else p++;
    seg_s.upd(i, p);
  }

  while(q--) {
    int l, r; cin >> l >> r;
    
    int min_pref = seg_p.qry(l, r + 1);
    int pref_sub = seg_p.qry(l - 1, l);

    int L = -1, R = -1, ci = 0;
    if(min_pref - pref_sub < 0) {
      int cnt = abs(min_pref - pref_sub);
      auto it = *lower_bound(all(mp[-1 + pref_sub]), l);
      L = it;

      auto it_ = *lower_bound(all(mp[min_pref]), l);
      R = it_;
      ci = cnt;
      assert(L <= R);
    }
    
    int pat = 0;

    if(L != -1 && R != -1) {
      pat = ci;
      int pi = 0;
      if(R + 1 <= r) {
        int min_suf = seg_s.qry(R + 1, r + 1);
        int suf_sub = seg_s.qry(r + 1, r + 2);
        int to_add = 0;
        if(min_suf - suf_sub < 0) {
          to_add = abs(min_suf - suf_sub);
        }
        pat += to_add;
      }
      
      if(L <= R) {
        int min_suf = seg_s.qry(L, R + 1);
        int suf_sub = seg_s.qry(R + 1, R + 2);
        min_suf -= suf_sub;
        int to_add = 0;
        if(min_suf < 0 && abs(min_suf) > suf_sub + pat) {
          to_add = abs( abs(min_suf) - (suf_sub + pat));
        }
        pat += to_add;
      }

      if(l <= L - 1) {
        int min_suf = seg_s.qry(l, L);
        int suf_sub = seg_s.qry(L, L + 1);
        min_suf -= suf_sub;
        int to_add = 0;
        if(min_suf < 0 && abs(min_suf) > suf_sub + pat) {
          to_add = abs( abs(min_suf) - (suf_sub + pat));
        }
        pat += to_add;
      }
    } else {
      int min_suf = seg_s.qry(l, r + 1);
      int suf_sub = seg_s.qry(r + 1, r + 2);
      int to_add = 0;
      if(min_suf - suf_sub < 0) {
        to_add = abs(min_suf - suf_sub);
      }
      pat += to_add;
    }

    cout << pat << '\n';
  }
}

int main() {
  setIO();
 
  auto solve = [&](int test_case)-> void {
    while(test_case--) {
      solve_();
    }
  };
 
  int test_cases = 1;
  // cin >> test_cases;
  solve(test_cases);
 
  return 0;
} 

Compilation message (stderr)

election.cpp: In function 'void solve_()':
election.cpp:208:11: warning: unused variable 'pi' [-Wunused-variable]
  208 |       int pi = 0;
      |           ^~
election.cpp: In function 'void setIO(std::string)':
election.cpp:90:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |     freopen((str + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
election.cpp:91:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     freopen((str + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
election.cpp:93:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |     freopen("input.txt", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
election.cpp:94:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |     freopen("output.txt", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 28
• Subtask 2: 0 / 54
• Subtask 3: 0 / 18