Language: C++

#define _USE_MATH_DEFINES
#include<iostream>
#include<string>
#include<queue>
#include<cmath>
#include<map>
#include<set>
#include<list>
#include<iomanip>
#include<vector>
#include<random>
#include<functional>
#include<algorithm>
#include<stack>
#include<cstdio>
#include<bitset>
#include<unordered_map>
#include<climits>
#include<fstream>
using namespace std;
///////////////////library zone!!!!!!!!!!!!!!!!!!!!!!!!!!!!
typedef long long ll;
typedef long double ld;
#define all(a) (a).begin(),(a).end()
#define EPS (1e-5)
#define bit(n,k) ((n>>k)&1)
const ll Mod = 1000000007;
const ll mod = 998244353;
struct H {
	ll x, y;
	bool operator<(const H& b) const {
		if (x != b.x) return x < b.x;
		return y < b.y;
	}
	bool operator>(const H & b) const {
		if (x != b.x) return x > b.x;
		return y > b.y;
	}
	bool operator==(const H & b) const { return x == b.x && y == b.y; }
	bool operator!=(const H & b) const { return (*this) != b; }
};
struct P {
	ll pos, cost;
	bool operator<(const P& b) const { return cost < b.cost; }
	bool operator>(const P& b) const { return cost > b.cost; }
};
struct B {
	ll to, cost;
};
struct E {
	ll from, to, cost;
	bool operator<(const E& b) const { return cost < b.cost; }
	bool operator>(const E& b) const { return cost > b.cost; }
};
template<typename T, typename U>
void chmin(T & a, U b) {
	if (a > b) a = b;
}
template<typename T, typename U>
void chmax(T & a, U b) {
	if (a < b) a = b;
}
template<typename T>
T max_0(T a) {
	if (a < 0) return 0;
	return a;
}
template<typename T>
T min_0(T a) {
	if (a > 0) return 0;
	return a;
}
ll read() {
	ll u;
	ll k = scanf("%lld", &u);
	return u;
}
ll gcd(ll i, ll j) {
	if (i > j) swap(i, j);
	if (i == 0) return j;
	return gcd(j % i, i);
}
ll mod_pow(ll x, ll n, ll p) {
	ll res = 1;
	while (n > 0) {
		if (n & 1) res = res * x % p;
		x = x * x % p;
		n >>= 1;
	}
	return res;
}//x^n%p
const ll Inf = 3023372036854775807;
const int inf = 1500000000;
#define int long long
//----------------------------------------------------
int n;
struct A {
	int x, r;
	bool operator<(A b) {
		return x + r < b.x + b.r;
	}
};
A a[200000];
vector<int>v;
int dat[200000];
int m = 1;
void update(int x, int t) {
	x += m - 1;
	dat[x] = t;
	while (x > 0) {
		x = (x - 1) / 2;
		dat[x] = max(dat[x + 2 + 1], dat[x * 2 + 2]);
	}
}
int query(int i, int a, int b, int l, int r) {
	if (b <= l || r <= a) return 0;c
	if (a <= l && r <= b) {
		return dat[i];
	}
	return max(query(i * 2 + 1, a, b, l, (l + r) / 2), 
		query(i * 2 + 2, a, b, (l + r) / 2, r));
}
signed main() {
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a[i].x >> a[i].r;
		v.push_back(a[i].x + a[i].r);
		v.push_back(a[i].x - a[i].r);
	}
	sort(a, a + n);
	sort(all(v));
	v.erase(unique(all(v)), v.end());
	while (m < n) m *= 2;
	int ans = 0;
	for (int i = 0; i < n; i++) {
		int s = upper_bound(all(v), a[i].x - a[i].r) - v.begin();
		int e = lower_bound(all(v), a[i].x - a[i].r) - v.begin();
		int k = query(0, s, m, 0, m);
		ans = max(ans, k + 1);
		update(e, k + 1);
	}
	cout << ans << endl;
}

Compiler output:
a.cc: In function 'long long int query(long long int, long long int, long long int, long long int, long long int)':
a.cc:116:40: error: 'c' was not declared in this scope
  116 |         if (b <= l || r <= a) return 0;c
      |                                        ^