Submission #163978

#	Time	Username	Problem	Language	Result	Execution time	Memory
163978		Leonardo_Paes	Street Lamps (APIO19_street_lamps)	C++17	40 / 100	242 ms	30968 KiB

street_lamps

#include <bits/stdc++.h>

using namespace std;

const int maxn = 3e5+10;

int n, q;

string initial;

vector<int> toggles;

vector<int> events[maxn];

string query[maxn];

int aa[maxn], bb[maxn];

bool subtask_1(){
    return n<=100 and q<=100;
}

bool subtask_2(){
    bool ok = true;

    for(int i=1; i<=q; i++){
        if(query[i][0]=='q' and bb[i]-aa[i]!=1) ok = false;
    }

    return ok;
}

inline bool check(int x, int a, int b){
    string now = initial;

    for(int i=0; i<=x; i++){
        now[toggles[i]] = 1;
    }

    bool ok = true;

    for(int i=a; i<b; i++){
        if(now[i] == '0') ok = false;
    }

    return ok;
}

int main(){
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);

    cin >> n >> q;

    initial.resize(n+2);

    for(int i=1; i<=n; i++){
        cin >> initial[i];
        if(initial[i]=='1') events[i].push_back(0);
    }

    for(int i=1; i<=q; i++){
        cin >> query[i];
        if(query[i][0] == 'q') cin >> aa[i] >> bb[i];
        else cin >> aa[i];
    }

    if(subtask_1()){
        toggles.push_back(0);

        for(int t=1; t<=q; t++){
            string op = query[t];

            if(op[0] == 'q'){
                int a = aa[t], b = bb[t];

                string now = initial;

                int ans = 0;

                for(int i=0; i<toggles.size(); i++){
                    if(now[toggles[i]]=='0') now[toggles[i]] = '1';
                    else now[toggles[i]] = '0';

                    bool ok = true;

                    for(int j=a; j<b; j++) if(now[j] == '0') ok = false;

                    if(ok) ans++;
                }

                cout << ans << '\n';

                toggles.push_back(0);
            }
            else{
                int i = aa[t];

                toggles.push_back(i);
            }
        }
    }
    else if(subtask_2()){
        for(int t=1; t<=q; t++){
            string op = query[t];

            if(op[0] == 'q'){
                int a = aa[t], b = bb[t];

                int ans = 0;

                for(int i=0; i<events[a].size(); i++){
                    if(i%2){
                        ans += events[a][i] - events[a][i-1];
                    }
                }

                if(events[a].size()%2) ans += t - events[a].back();

                cout << ans << '\n';
            }
            else{
                int i = aa[t];

                events[i].push_back(t);
            }
        }
    }
    else{
        for(int t=1; t<=q; t++){
            string op = query[t];

            if(op[0] == 'q'){
                toggles.push_back(0);

                int a = aa[t], b = bb[t];

                int ini = 0, fim = t-1, meio, ans = t-1;

                while(ini <= fim){
                    meio = (ini+fim) >> 1;

                    if(check(meio, a, b)){
                        fim = meio - 1;
                        ans = meio;
                    }
                    else{
                        ini = meio + 1;
                    }
                }

                cout << t-ans << '\n';
            }
            else{
                int i = aa[t];

                toggles.push_back(i);
            }
        }
    }

    return 0;
}

Compilation message (stderr)

street_lamps.cpp: In function 'int main()':
street_lamps.cpp:80:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 for(int i=0; i<toggles.size(); i++){
                              ~^~~~~~~~~~~~~~~
street_lamps.cpp:111:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
                 for(int i=0; i<events[a].size(); i++){
                              ~^~~~~~~~~~~~~~~~~
street_lamps.cpp:107:32: warning: unused variable 'b' [-Wunused-variable]
                 int a = aa[t], b = bb[t];
                                ^

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20