Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {

	sc := bufio.NewScanner(os.Stdin)
	sc.Scan()
	args := strings.Split(sc.Text(), " ")
	n, _ := strconv.Atoi(args[0])
	t, _ := strconv.ParseInt(args[1], 10, 64)

	q, _ := strconv.Atoi(args[2])

	pos := make([]int64, n)
	direction := make([]bool, n)

	for i := 0; i < n; i++ {
		sc.Scan()
		args = strings.Split(sc.Text(), " ")

		pos[i], _ = strconv.ParseInt(args[0], 10, 64)
		q, _ := strconv.Atoi(args[1])
		if q == 1 {
			direction[i] = true
		}
	}

	qq := make([]int, q)
	for i := 0; i < q; i++ {
		sc.Scan()
		args = strings.Split(sc.Text(), " ")

		qq[i], _ = strconv.Atoi(args[0])
	}

	ans(n, q, t, pos, direction, qq)

}

func ans(n, q int, t int64, pos []int64, dir []bool, qq []int) {

	colleation := []int64{} // syoutotu positon

	for i := 1; i < n; i++ {
		if dir[i-1] == dir[i] {
			continue
		}
		colleation = append(colleation, (pos[i-1]+pos[i])/2)

	}
	//fmt.Println(colleation)
	for i := 0; i < q; i++ {
		var ans int64
		ans = int64(-9999999)
		if dir[qq[i]-1] == true {
			// 東向きなら現ポジから＋方向で一番近い衝突点との距離を求めて、Tとの差が
			for _, v := range colleation {
				if v <= pos[qq[i]-1] {
					continue
				} else {
					// 衝突予定点が確定。衝突点との距離がT以下なら衝突点で停止
					if v-pos[qq[i]-1] <= t {
						ans = v
					} else {
						ans = pos[qq[i]-1] + int64(t)
					}
					break
				}
			}
			if ans == -9999999 {
				ans = pos[qq[i]-1] + int64((t))
			}

		} else {
			// nishi向きなら現ポジから-方向で一番近い衝突点との距離を求めて、Tとの差が
			for j := len(colleation); j > 0; j-- {
				if colleation[j-1] >= pos[qq[i]-1] {
					continue
				}
				v := colleation[j-1]
				//fmt.Printf("hoge=%d\n", v)
				// 衝突予定点が確定
				if pos[qq[i]-1]-v <= t {
					ans = v
				} else {
					ans = pos[qq[i]-1] - int64((t))
				}
				break

			}
			if ans == -9999999 {
				ans = pos[qq[i]-1] - int64((t))
			}

		}
		fmt.Printf("%d\n", ans)

	}

}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef pair<ll,ll> mp;
ll inf = 2*1e18;


int main(){
    ll n,t,q;
    cin>>n>>t>>q;
    vector<mp> a(n);
    vector<ll> ans(n);
    for(int i=0;i<n;i++) cin>>a[i].first>>a[i].second;
    ll meet = -inf;
    stack<ll> st;
    st.push( -inf );
    for(int i=0;i<n;i++){
	if( a[i].second==1){
	    st.push( a[i].first );
	}else{
	    ll l = st.top();
	    if( st.size() != 1 ) st.pop();
	    if( meet <= l )meet = max(meet , (l+a[i].first)/2 );
	    meet = max(meet , a[i].first - t);
	    ans[i] = meet;
	}
    }
 //   cout<<"PL"<<endl;
    meet = inf;
    stack<ll> st2;
   // while(!st.empty())st.pop();
    st2.push(inf);
    for(int i=n-1;i>=0;i--){
	if(a[i].second==2){
	    st2.push( a[i].first );
	}else{
	    ll  r = st2.top();
	   // cout<<st2.top()<<' '<<a[i].first<<endl;
	    if( st2.size() != 1 ) st2.pop();
	 //   cout<<i<<' '<<meet<<' '<< ( r+a[i].first)/2<<' ' << a[i].first+t< <endl;
	    if( r <=  meet ) meet = min(meet , ( r + a[i].first )/2 );
	    meet = min(meet , a[i].first + t );
	    ans[i]  = meet;
	    
	}
    }
   // cout<<"ok"<<endl;
    for(int i=0;i<q;i++){
	ll qq;
	cin>>qq;qq--;
	cout<<ans[qq]<<endl;
    }


	return 0;
}

C++: #include<bits/stdc++.h>
#define PB push_back
#define MP make_pair
#define FI first
#define SE second
using namespace std;
typedef pair<int,int> pii;
static const int inf = 1ll<<60;
static const int MAX_N = 100000;

int N,T,Q;
vector<pii> A;
int flg[MAX_N];
int table[MAX_N];
int next[MAX_N];

signed main(){
    memset(next,-1,sizeof(next));
    cin>>N>>T>>Q;
    for(int i=0;i<N;++i){
        int a,d;
        cin>>a>>d;
        if(d!=1)d=-1;
        A.PB(pii(a,d));
    }
    sort(A.begin(),A.end());
    int maxd=0;
    int t=0;
    for(int i=0;i<N;++i){
        if(flg[i]==1)continue;
        if(A[i].SE!=1||A[i+1].SE!=-1){
            if(A[i].SE==1)table[i]=t;
            else table[i]=t-1;
            continue;
        }
        int D=abs(A[i].FI-A[i+1].FI)/2;
        if(D<=T){
            maxd=max(D,maxd);
            A[i].FI+=A[i].SE*D;
            A[i+1].FI+=A[i+1].SE*D;
            flg[i]=flg[i+1]=1;
            next[t]=A[i].FI;
            t++;
        }
    }
    for(int i=0;i<N;++i){
        if(flg[i]==1)continue;
        if(A[i].SE==1)A[i].FI+=maxd;
        else A[i].FI-=maxd;
    }
    T-=maxd;
    for(int i=0;i<N;++i){
        if(flg[i]==1)continue;
        if(A[i].SE==1){
            int k=table[i];
            if(next[k]==-1)A[i].FI+=T;
            else{
                int d=abs(A[i].FI-next[k]);
                if(d<=T)A[i].FI=next[k];
                else A[i].FI+=T;
            }
        }
        else{
            int k=table[i];
            //cout<<next[k]<<endl;
            if(next[k]==-1)A[i].FI-=T;
            else{
                int d=abs(A[i].FI-next[k]);
                if(d<=T)A[i].FI=next[k];
                else A[i].FI-=T;
            }
        }
    }
    for(int i=0;i<Q;++i){
        int q;
        cin>>q;
        q--;
        cout<<A[q].FI<<endl;
    }
}

C++: #include<bits/stdc++.h>
#define rep(i,n)for(ll i=0;i<n;i++)
using namespace std;
typedef long long ll;

ll n, t, q, x[100000], a[100000];
int d[100000];

int main() {
	scanf("%lld%lld%lld", &n, &t, &q);
	rep(i, n)scanf("%lld%d", &a[i], &d[i]);
	rep(i, q)scanf("%lld", &x[i]);
	rep(i, n - 1) {
		if (d[i] == 1 && d[i + 1] == 2 && a[i + 1] - a[i] <= t * 2) {
			d[i] = d[i + 1] = 0;
			a[i] = a[i + 1] = a[i] + (a[i + 1] - a[i]) / 2;
		}
	}
	rep(i, n) {
		rep(i, n) {
			if (i < n - 1 && d[i] == 1 && !d[i + 1] && a[i + 1] - a[i] <= t) {
				a[i] = a[i + 1];
				d[i] = 0;
			}
			if (0 < i&&d[i] == 2 && !d[i - 1] && a[i] - a[i - 1] <= t) {
				a[i] = a[i - 1];
				d[i] = 0;
			}
		}
	}
	rep(j, q) {
		int i = x[j] - 1;
		if (d[i] == 1)printf("%lld\n", a[i] + t);
		else if (d[i])printf("%lld\n", a[i] - t);
		else printf("%lld\n", a[i]);
	}
}

C++: #include <iostream>
#include <vector>
#include <algorithm>

constexpr int MAX_N = 100000;
constexpr long long MAX_T = 1000000000000000000;

long long N, T, Q;

long long pos[MAX_N], target[MAX_N];
int dir[MAX_N];
std::vector<long long> stops;

void solve();

int main(){
	std::ios::sync_with_stdio(false);
	std::cin.tie(0);

	std::cin >> N >> T >> Q;

	for(int i = 0; i < N; ++i){
		std::cin >> pos[i] >> dir[i];
	}

	for(int i = 0; i < N - 1; ++i){
		if(dir[i] == 1 && dir[i + 1] == 2 && (pos[i + 1] - pos[i]) <= (T * 2)){
			stops.push_back((pos[i + 1] + pos[i]) / 2);
		}
	}

	for(int i = 0; i < Q; ++i){
		int input;
		std::cin >> input;
		--input;

		long long res = MAX_T;
		if(dir[input] == 1){ //When a citizen heads east.
			auto itr = std::lower_bound(stops.begin(), stops.end(), pos[input]);
			if(itr != stops.end() && *itr <= pos[input] + T){
				res = *itr;
			}
		}
		else{ //When a citizen heads west.
			auto itr = std::lower_bound(stops.begin(), stops.end(), pos[input] - T);
			while(itr != stops.end() && *itr <= pos[input]){
				res = *itr;
				++itr;
			}
		}

		if(res == MAX_T){
			if(dir[input] == 1){
				std::cout << pos[input] + T << std::endl;
			}
			else{
				std::cout << pos[input] - T << std::endl;
			}
		}
		else{
			std::cout << res <<  std::endl;
		}
	}

	return 0;
}