Submission #1103552

#	Time	Username	Problem	Language	Result	Execution time	Memory
1103552		LTTrungCHL	Election (BOI18_election)	C++17	100 / 100	791 ms	49368 KiB

election

///***LTT***///
/// ->NHAT QUOC GIA<- ///
#include<bits/stdc++.h>
//#pragma GCC optimize ("O3")
//#pragma GCC optimize ("unroll-loops")
//#pragma GCC target("popcnt")
//#define int long long
#define endl "\n"
#define F first
#define S second
#define pb push_back
using namespace std;
vector <int> lg2;
//void MAKE_LOG_ARR(int n){
//    lg2.resize(n + 3);
//    for (int i = 1;i <= n;++i){
//        lg2[i] = __lg(i);
//    }
//}
const long long oo = 1e9+7;
const int N = 5 * 1e5 + 10;
int n, q;
string s;
int a[N];
int tree[N * 4], lazy[N * 4];
vector <pair <int, int>> query[N];
vector <int> del;
int ans[N];
void down(int id, int l, int r){
    if (l != r){
        tree[id * 2] += lazy[id];
        tree[id * 2 + 1] += lazy[id];
        lazy[id * 2] += lazy[id];
        lazy[id * 2 + 1] += lazy[id];
    }
    lazy[id] = 0;
    return;
}
void update(int id, int l, int r, int u, int v, int val){
    if (lazy[id] != 0){
        down(id, l, r);
    }
    if (l > v or r < u) return;
    if (l >= u and r <= v){
        tree[id] += val;
        lazy[id] += val;
        return;
    }
    int mid = (l + r)/2;
    update(id * 2, l, mid, u, v, val);
    update(id * 2 + 1, mid + 1, r, u, v, val);
    tree[id] = min(tree[id * 2], tree[id * 2 + 1]);
    return;
}
int get(int id, int l, int r, int u, int v){
    if (u > n) return 0;
    if (lazy[id] != 0){
        down(id, l, r);
    }
    if (l > v or r < u) return oo;
    if (l >= u and r <= v){
        return tree[id];
    }
    int mid = (l + r)/2;
    return min(get(id * 2, l, mid, u, v), get(id * 2 + 1, mid + 1, r, u, v));
}
void solve(){
    cin >> n;
    cin >> s;
    for (int i = 0;i < s.size();++i){
        if (s[i] == 'C'){
            a[i + 1] = 1;
        }  else a[i + 1] = -1;
    }
    for (int i = 1;i <= n;++i){
        update(1,1,n,1,i,a[i]);
    }
    cin >> q;
    for (int i = 1;i <= q;++i){
        int l, r;
        cin >> l >> r;
        query[l].pb({r, i});
    }
    for (int i = n;i >= 1;--i){
        if (a[i] == 1){
            if (!del.empty()){
                int zz = del.back();
                update(1,1,n,1,zz,-1);
                del.pop_back();
            }
        } else {
            update(1,1,n,1,i,1);
            del.pb(i);
        }
        for (int j = 0;j < query[i].size();++j){
            int id = query[i][j].S;
            int r = query[i][j].F;
            int res = del.size();
            int ll = 0, rr = del.size() - 1;
            while (ll <= rr){
                int mid = (ll + rr)/2;
                if (del[mid] <= r){
                    rr = mid - 1;
                    res = mid;
                } else ll = mid + 1;
            }
            int sz = del.size() - 1;
//            cout << id <<" : ";
//            for (int z = 1;z <= n;++z){
//                cout << get(1,1,n,z,z) <<" ";
//            }
//            cout <<"\n";
//            cout << id <<" "<<(sz - res + 1) <<" "<<get(1,1,n,i,r) <<" "<< get(1,1,n,r + 1,r + 1) <<"\n";
            ans[id] = (sz - res + 1) + abs(min(0,get(1,1,n,i,r) - get(1,1,n,r + 1,r + 1)));
        }
    }
    for (int i = 1;i <= q;++i){
        cout << ans[i] <<"\n";
    }
    return;
}
int main(){
    ios_base::sync_with_stdio(NULL);
    cin.tie(NULL);
    cout.tie(NULL);
    if (fopen("ltt.inp", "r")){
        freopen("ltt.inp", "r", stdin);
        freopen("ltt.out", "w", stdout);
    }
//    int t;
//    cin >> t;
//    while(t--){
    solve();
//    }
    return 0;
}

Compilation message (stderr)

election.cpp: In function 'void solve()':
election.cpp:70:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   70 |     for (int i = 0;i < s.size();++i){
      |                    ~~^~~~~~~~~~
election.cpp:95:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |         for (int j = 0;j < query[i].size();++j){
      |                        ~~^~~~~~~~~~~~~~~~~
election.cpp: In function 'int main()':
election.cpp:127:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  127 |         freopen("ltt.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
election.cpp:128:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  128 |         freopen("ltt.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

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