C.cpp

#include<bits/stdc++.h>
using namespace std;
#define fo(i,n) for(i=0;i<n;i++)
#define fo2(i,start,end) for(i=start;i<=end;i++)
#define rfo(i,n) for(i=n-1;i>=0;i--)
#define lli long long int
#define ll long long int
#define deb(x) cout<<#x<<"="<<x<<endl
#define deb2(x,y) cout<<#x<<"="<<x<<","<<#y<<"="<<y<<endl
#define pb push_back
#define mp make_pair
#define F first
#define S second
#define all(x) x.begin(), x.end()
#define sortall(x) sort(all(x))
#define tr(it,a) for(auto it=a.begin(); it!=a.end();it++)
#define nl '\n'
#define PI 3.1415926535897932384626
#define mod 1000000007
typedef pair<int, int>	pii;
typedef pair<lli, lli>	pl;
typedef vector<int>		vi;
typedef vector<lli>		vl;
typedef vector<pii>		vpii;
typedef vector<pl>		vpl;
const ll inf=1e12;
void solve(){
    int i,j;
    int n;
    cin>>n;
    ll t[n+1],x[n],curr=0,dest=0,dir=0,count=0,temp,mn,mx;
    fo(i,n){
        cin>>t[i]>>x[i];
    }
    t[n]=1e12;
    fo(i,n){
        // deb2(curr,dest);
        if(curr==dest){
            dest=x[i];
        }
        temp=curr;
        if(dest>curr){
            dir=1;
        }
        else{
            dir=-1;
        }
        curr=curr+dir*(min((t[i+1]-t[i]),abs(dest-curr)));
        mn=min(temp,curr);
        mx=max(temp,curr);
        if(x[i]>=mn && x[i]<=mx){
            count++;
        }
    }
    cout<<count<<nl;
}

int main(){
    // freopen("input.txt", "r", stdin);
    // freopen("output.txt", "w", stdout);
    ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    int t=1;
    cin>>t;
    while(t--){
        solve();
    }
}