Submission #546066

#	Time	Username	Problem	Language	Result	Execution time	Memory
546066		Soul234	Election (BOI18_election)	C++14	100 / 100	577 ms	27984 KiB

election

#include<bits/stdc++.h>
using namespace std;

void DBG() { cerr << "]\n"; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << h; if(sizeof...(t)) cerr << ", ";
    DBG(t...);
}
#ifdef LOCAL
#define dbg(...) cerr << "[" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif // LOCAL

#define FOR(i,a,b) for(int i = (a) ; i<(b) ; i++)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for(int i = (b)-1 ; i>=(a) ; i--)
#define R0F(i,a) ROF(i,0,a)
#define each(e,a) for(auto &e : (a))
#define sz(v) (int)(v).size()
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pb push_back
#define tcT template<class T
#define nl "\n"

using ll = long long;
using vi = vector<int>;
using pi = pair<int,int>;
using str = string;
tcT> using V = vector<T>;
tcT> using pqg = priority_queue<T,vector<T>,greater<T>>;

void setIO(string NAME = "") {
    cin.tie(0)->sync_with_stdio(0);
    if(sz(NAME)) {
        freopen((NAME + ".inp").c_str(),"r",stdin);
        freopen((NAME + ".out").c_str(),"w",stdout);
    }
}

const int MX = 1<<19;

struct Nod {
    int mncst, mxp, mxs, sum;
};

Nod comb(const Nod&lf, const Nod&rh) {
    return {
        max({lf.mxp + rh.mxs, lf.sum + rh.mncst, lf.mncst + rh.sum}),
        max(lf.mxp, lf.sum + rh.mxp),
        max(rh.mxs, rh.sum + lf.mxs),
        lf.sum + rh.sum,
    };
}

Nod st[MX<<1];
int N;
str s;

void build(int ind = 1, int L = 1, int R = N) {
    if(L == R) {
        if(s[L-1] == 'T') st[ind] = {1, 1, 1, 1};
        else st[ind] = {0,0,0,-1};
    }
    else {
        int mid = (L + R) >> 1;
        build(ind<<1, L, mid);
        build(ind<<1|1, mid+1, R);
        st[ind] = comb(st[ind<<1], st[ind<<1|1]);
    }
}

Nod query(int l, int r, int ind = 1, int L = 1, int R = N) {
    if(l > R || r < L) return {0,0,0,0};
    if(l <= L && R <= r) return st[ind];
    int mid = (L + R) >> 1;
    return comb(query(l,r,ind<<1, L, mid), query(l,r,ind<<1|1, mid+1, R));
}

void solve() {
    cin>>N>>s;
    build();
    int Q;
    cin>>Q;
    while(Q--) {
        int l, r;
        cin>>l>>r;
        cout << query(l,r).mncst << nl;
    }
}

int main() {
    setIO();

    int t=1;
    //cin>>t;
    while(t-->0) {
        solve();
    }

    return 0;
}

Compilation message (stderr)

election.cpp: In function 'void setIO(std::string)':
election.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen((NAME + ".inp").c_str(),"r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
election.cpp:38:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |         freopen((NAME + ".out").c_str(),"w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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