TSM

#include <bits/stdc++.h>
#define maxN 1000005
#define lsb(x) ((x)&(-x))
using namespace std;
int aib[maxN];
int viz[maxN];
int n,last,x,op;

class InParser {
private:
    FILE *fin;
    char *buff;
    int sp;

    char read_ch() {
        ++sp;
        if (sp==4096) {
            sp=0;
            fread(buff,1,4096,fin);
        }
        return buff[sp];
    }

public:
    InParser(const char* nume) {
        fin=fopen(nume,"r");
        buff=new char[4096]();
        sp=4095;
    }

    InParser& operator >> (int &n) {
        char c;
        while(!isdigit(c=read_ch()) && c!='-');
        int sgn=1;
        if(c=='-'){
            n=0;
            sgn=-1;
        }else
            n=c-'0';
        while(isdigit(c=read_ch()))
            n=10*n+c-'0';
        n*=sgn;
        return *this;
    }

    InParser& operator >> (long long &n) {
        char c;
        n=0;
        while (!isdigit(c=read_ch()) && c!='-');
        long long sgn=1;
        if(c=='-'){
            n=0;
            sgn=-1;
        }else
            n=c-'0';
        while(isdigit(c=read_ch()))
            n=10*n+c-'0';
        n*=sgn;
        return *this;
    }
};

class OutParser{
private:
    FILE *fout;
    char *buff;
    int sp;

    void write_ch(char ch) {
        if (sp==50000){
            fwrite(buff,1,50000,fout);
            sp=0;
            buff[sp++]=ch;
        } else {
            buff[sp++]=ch;
        }
    }

public:
    OutParser(const char* name) {
        fout=fopen(name,"w");
        buff=new char[50000]();
        sp=0;
    }
    ~OutParser() {
        fwrite(buff,1,sp,fout);
        fclose(fout);
    }

    OutParser& operator << (int vu32) {
        if (vu32<=9) {
            write_ch(vu32+'0');
        } else {
            (*this)<<(vu32/10);
            write_ch(vu32%10+'0');
        }
        return *this;
    }

    OutParser& operator << (long long vu64) {
        if (vu64<=9) {
            write_ch(vu64+'0');
        } else {
            (*this)<<(vu64/10);
            write_ch(vu64%10+'0');
        }
        return *this;
    }

    OutParser& operator << (char ch) {
        write_ch(ch);
        return *this;
    }
    OutParser& operator << (const char *ch) {
        while(*ch){
            write_ch(*ch);
            ++ch;
        }
        return *this;
    }
};

void update(int val)
{
    for(int i=val;i<maxN;i+=lsb(i))
        aib[i]++;
}

void _delete(int val)
{
    for(int i=val;i<maxN;i+=lsb(i))
        if(aib[i])
            aib[i]--;
}

int query(int pos)
{
    int res=0;
    for(int i=pos;i>0;i-=lsb(i))
        res+=aib[i];
    return res;
}

int _search(int val)
{
    int step,i;
    for(step=1;step<maxN;step<<=1);
    for(i=0;step;step>>=1)
        if(i+step<=1000000)
            if(val>=aib[i+step])
            {
                i+=step;
                val-=aib[i];
            }
    i++;
    while(!viz[i] && viz[i]<val) /* mai putine iteratii decat ma asteptam */
        i++,val-=viz[i];
    return i;
}

int main()
{
    InParser f("tsm.in");
    OutParser g("tsm.out");
    f>>n;
    while(n--)
    {
        f>>op;
        if(op==1){
            f>>x;
            viz[x]++;
            if(viz[x]==1)
                update(x);
        }
        if(op==2){
            f>>x;
            last=_search(x-1);
            g<<last<<'\n';
        }
        if(op==3){
            g<<_search(0)<<'\n';
        }
        if(op==4){
            viz[last]--;
            if(viz[last]==0)
                _delete(last);
        }
    }
    return 0;
}