Submission #170209

#	Time	Username	Problem	Language	Result	Execution time	Memory
170209		arnold518	Street Lamps (APIO19_street_lamps)	C++14	100 / 100	1787 ms	66748 KiB

street_lamps

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

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 3e5;

int N, Q, A[MAXN+10];

set<int> S, E;
pii range(int x) { return pii(*(--S.upper_bound(x)), *E.lower_bound(x)); }

pll operator + (const pll &p, const pll &q) { return pll(p.first+q.first, p.second+q.second); }

struct Data
{
    int t, y, x; pll val;
    bool operator < (const Data &p) const { return x<p.x; }
};
vector<Data> todo;

struct BIT
{
    pll tree[MAXN+10];
    void update(int i, pll v) { for(; i<=N; i+=(i&-i)) tree[i]=tree[i]+v; }
    pll query(int i) { pll ret(0, 0); for(; i>0; i-=(i&-i)) ret=ret+tree[i]; return ret; }
    void flush(int i) { for(; i<=N; i+=(i&-i)) tree[i]=pll(0, 0); }
}bit;

void update(int y, int x, pll v) { todo.push_back({0, N-y+1, x, v}); }
void query(int y, int x, ll v) { todo.push_back({1, N-y+1, x, {v, todo.size()}}); }

pll ans[MAXN*10+10];

void solve(int s, int e)
{
    int i, j;
    if(s==e)
    {
        if(todo[s].t)
        {
            pll ret=ans[s];
            printf("%lld\n", ret.first-ret.second*todo[s].val.first);
        }
        return;
    }

    int mid=s+e>>1;
    solve(s, mid);

    vector<Data> A, B;
    for(i=s; i<=mid; i++) if(!todo[i].t) A.push_back(todo[i]);
    for(i=mid+1; i<=e; i++) if(todo[i].t) B.push_back(todo[i]);

    sort(A.begin(), A.end());
    sort(B.begin(), B.end());

    for(i=0, j=0; i<B.size(); i++)
    {
        for(; j<A.size() && A[j].x<=B[i].x; j++) bit.update(A[j].y, A[j].val);
        ans[B[i].val.second]=ans[B[i].val.second]+bit.query(B[i].y);
    }
    for(j=0; j<A.size(); j++) bit.flush(A[j].y);

    solve(mid+1, e);
}

int main()
{
    int i, j;

    scanf("%d%d", &N, &Q);
    for(i=1; i<=N; i++) scanf("%1d", &A[i]);

    set<int>::iterator it, jt;
    for(i=1; i<=N; i++) if(A[i-1]==0 && A[i]==1) S.insert(i);
    for(i=1; i<=N; i++) if(A[i]==1 && A[i+1]==0) E.insert(i);

    for(it=S.begin(), jt=E.begin(); it!=S.end() && jt!=E.end(); it++, jt++) update(*jt, *it, pll(Q+1, 1));

    for(i=1; i<=Q; i++)
    {
        char st[10];
        int a, b;

        scanf("%s", st);
        if(st[0]=='t')
        {
            scanf("%d", &a);

            if(A[a]==0)
            {
                if(S.find(a+1)!=S.end() && E.find(a-1)!=E.end())
                {
                    update(range(a-1).second, range(a-1).first, pll(-(Q-i+1), -1));
                    update(range(a+1).second, range(a+1).first, pll(-(Q-i+1), -1));
                    S.erase(a+1);
                    E.erase(a-1);
                }
                else if(S.find(a+1)!=S.end())
                {
                    update(range(a+1).second, range(a+1).first, pll(-(Q-i+1), -1));
                    S.erase(a+1);
                    S.insert(a);
                }
                else if(E.find(a-1)!=E.end())
                {
                    update(range(a-1).second, range(a-1).first, pll(-(Q-i+1), -1));
                    E.erase(a-1);
                    E.insert(a);
                }
                else
                {
                    S.insert(a);
                    E.insert(a);
                }
                update(range(a).second, range(a).first, pll((Q-i+1), 1));
                A[a]=1;
            }
            else
            {
                int s, e;
                tie(s, e)=range(a);

                update(range(a).second, range(a).first, pll(-(Q-i+1), -1));
                if(s==e)
                {
                    S.erase(a);
                    E.erase(a);
                }
                else if(s==a)
                {
                    S.erase(a);
                    S.insert(a+1);
                    update(range(a+1).second, range(a+1).first, pll((Q-i+1), 1));
                }
                else if(e==a)
                {
                    E.erase(a);
                    E.insert(a-1);
                    update(range(a-1).second, range(a-1).first, pll((Q-i+1), 1));
                }
                else
                {
                    S.insert(a+1);
                    E.insert(a-1);
                    update(range(a-1).second, range(a-1).first, pll((Q-i+1), 1));
                    update(range(a+1).second, range(a+1).first, pll((Q-i+1), 1));
                }
                A[a]=0;
            }
        }
        else
        {
            scanf("%d%d", &a, &b); b--;
            query(b, a, Q-i+1);
        }
    }

    solve(0, todo.size()-1);
}

Compilation message (stderr)

street_lamps.cpp: In function 'void solve(int, int)':
street_lamps.cpp:50:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
     int mid=s+e>>1;
             ~^~
street_lamps.cpp:60:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(i=0, j=0; i<B.size(); i++)
                   ~^~~~~~~~~
street_lamps.cpp:62:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(; j<A.size() && A[j].x<=B[i].x; j++) bit.update(A[j].y, A[j].val);
               ~^~~~~~~~~
street_lamps.cpp:65:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(j=0; j<A.size(); j++) bit.flush(A[j].y);
              ~^~~~~~~~~
street_lamps.cpp: In function 'int main()':
street_lamps.cpp:72:12: warning: unused variable 'j' [-Wunused-variable]
     int i, j;
            ^
street_lamps.cpp:74:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d", &N, &Q);
     ~~~~~^~~~~~~~~~~~~~~~
street_lamps.cpp:75:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     for(i=1; i<=N; i++) scanf("%1d", &A[i]);
                         ~~~~~^~~~~~~~~~~~~~
street_lamps.cpp:88:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%s", st);
         ~~~~~^~~~~~~~~~
street_lamps.cpp:91:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d", &a);
             ~~~~~^~~~~~~~~~
street_lamps.cpp:157:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf("%d%d", &a, &b); b--;
             ~~~~~^~~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20