Submission #440492

#	Time	Username	Problem	Language	Result	Execution time	Memory
440492		VladM	Street Lamps (APIO19_street_lamps)	C++14	40 / 100	820 ms	11628 KiB

street_lamps

#include <bits/stdc++.h>

using namespace std;

#define DIM 300007

#define INF 1000000007

struct Q
{
    int r, a, b;
};

vector<Q> quer;

long long n, q, nom, it, flag, a, b, res;

string s[107], r;

void solve1(string st)
{
    s[0]=st;
    s[0]='&'+s[0];
    nom=0;
    for(int h=1; h<=q; h++)
    {
        if(quer[h].r==1) r="t";
        else r="s";
        if(r[0]=='t')
        {
            it=quer[h].a;
            nom++;
            s[nom]=s[nom-1];
            if(s[nom][it]=='0') s[nom][it]='1';
            else s[nom][it]='0';
            continue;
        }
        a=quer[h].a;
        b=quer[h].b;
        res=0;
        for(int k=0; k<=nom; k++)
        {
            flag=0;
            for(int i=a; i<b; i++)
            {
                if(s[k][i]=='0')
                {
                    flag=1;
                    break;
                }
            }
            if(flag==0) res++;
        }
        nom++;
        s[nom]=s[nom-1];
        cout<<res<<endl;
    }
    return;
}

void solve2(string st)
{
    string s, r;
    long long a, b, it;
    vector<long long> lst, ans;
    lst.resize(n+7);
    ans.resize(n+7);
    s=st;
    s='&'+s;
    for(int i=1; i<=n; i++)  lst[i]=0;
    for(int i=1; i<=q; i++)
    {
        if(quer[i].r==1) r="t";
        else r="s";
        if(r[0]=='t')
        {
            it=quer[i].a;
            if(s[it]=='1') ans[it]+=i-lst[it];
            if(s[it]=='1') s[it]='0';
            else s[it]='1';
            lst[it]=i;
            continue;
        }
        a=quer[i].a;
        b=quer[i].b;
        if(s[a]=='1') ans[a]+=i-lst[a];
        lst[a]=i;
        cout<<ans[a]<<endl;
    }
    return;
}

int t[4*DIM];

void BuildTree(int v, int tl, int tr, string &s)
{
    if(tl==tr)
    {
        if(s[tl]=='1') t[v]=0;
        else t[v]=INF;
        return;
    }
    int tm=(tl+tr)>>1;
    BuildTree(2*v+1, tl, tm, s);
    BuildTree(2*v+2, tm+1, tr, s);
    t[v]=max(t[2*v+1], t[2*v+2]);
    return;
}

void update(int v, int tl, int tr, int x, int val)
{
    if(x<tl || tr<x) return;
    if(tl==tr)
    {
        t[v]=val;
        return;
    }
    int tm=(tl+tr)>>1;
    update(2*v+1, tl, tm, x, val);
    update(2*v+2, tm+1, tr, x, val);
    t[v]=max(t[2*v+1], t[2*v+2]);
    return;
}

int get_max(int v, int tl, int tr, int L, int R)
{
    if(R<tl || tr<L) return -INF;
    if(L<=tl && tr<=R) return t[v];
    int tm=(tl+tr)>>1;
    int mx1=get_max(2*v+1, tl, tm, L, R);
    int mx2=get_max(2*v+2, tm+1, tr, L, R);
    return max(mx1, mx2);
}

void solve3(string st)
{
    string s='&'+st;
    BuildTree(0, 1, n, s);
    for(int i=1; i<=q; i++)
    {
        if(quer[i].r==1)
        {
            update(0, 1, n, quer[i].a, i);
            continue;
        }
        int a, b;
        a=quer[i].a;
        b=quer[i].b;
        int mx=get_max(0, 1, n, a, b-1);
        if(mx==INF) cout<<0<<endl;
        cout<<i-mx<<endl;
    }
}

int main()
{
    cin>>n>>q;
    cin>>s[0];
    quer.push_back({0, 0, 0});
    for(int i=1; i<=q; i++)
    {
        cin>>r;
        if(r[0]=='t')
        {
            cin>>it;
            quer.push_back({1, it, 0});
            continue;
        }
        cin>>a>>b;
        if(b-a!=1) flag=1;
        quer.push_back({2, a, b});
    }
    if(n<=100 && q<=100) solve1(s[0]);
    else if(flag==0) solve2(s[0]);
    else solve3(s[0]);
    return 0;
}

Compilation message (stderr)

street_lamps.cpp: In function 'void solve2(std::string)':
street_lamps.cpp:64:18: warning: variable 'b' set but not used [-Wunused-but-set-variable]
   64 |     long long a, b, it;
      |                  ^
street_lamps.cpp: In function 'int main()':
street_lamps.cpp:166:32: warning: narrowing conversion of 'it' from 'long long int' to 'int' [-Wnarrowing]
  166 |             quer.push_back({1, it, 0});
      |                                ^~
street_lamps.cpp:171:28: warning: narrowing conversion of 'a' from 'long long int' to 'int' [-Wnarrowing]
  171 |         quer.push_back({2, a, b});
      |                            ^
street_lamps.cpp:171:31: warning: narrowing conversion of 'b' from 'long long int' to 'int' [-Wnarrowing]
  171 |         quer.push_back({2, a, b});
      |                               ^

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