Submission #3501949

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Source Code Expand

#include <bits/stdc++.h>

#define For(i, l, r) for(register int i = (l), i##end = (int)(r); i <= i##end; ++i)
#define Fordown(i, r, l) for(register int i = (r), i##end = (int)(l); i >= i##end; --i)
#define Set(a, v) memset(a, v, sizeof(a))
#define Cpy(a, b) memcpy(a, b, sizeof(a))
#define debug(x) cout << #x << ": " << (x) << endl
#define DEBUG(...) fprintf(stderr, __VA_ARGS__)
#define pb push_back

using namespace std;

template<typename T> inline bool chkmin(T &a, T b) {return b < a ? a = b, 1 : 0;}
template<typename T> inline bool chkmax(T &a, T b) {return b > a ? a = b, 1 : 0;}

inline int read() {
    int x(0), sgn(1); char ch(getchar());
    for (; !isdigit(ch); ch = getchar()) if (ch == '-') sgn = -1;
    for (; isdigit(ch); ch = getchar()) x = (x * 10) + (ch ^ 48);
    return x * sgn;
}

void File() {
#ifdef zjp_shadow
	freopen ("E.in", "r", stdin);
	freopen ("E.out", "w", stdout);
#endif
}

const int N = 1e5 + 1e3;

struct Node {
	int x, y, id;
} lt[N];

struct Cmp {
	inline bool operator () (const Node &lhs, const Node &rhs) {
		return lhs.x != rhs.x ? lhs.x < rhs.x : lhs.y < rhs.y;
	}
};

vector<int> G[N]; int con[N];

inline void Add(int u, int v) { G[u].pb(v); G[v].pb(u); }

int n, a, b, dis;
void Work(int d) {
	sort(lt + 1, lt + n + 1, Cmp());
	int l = 1, r = 0, pos = 1;
	For (i, 1, n) {
		while (l < n && (lt[l].x < lt[i].x - dis || (lt[l].x == lt[i].x - dis && lt[l].y < lt[i].y - d))) ++ l;
		while (r < n && (lt[r + 1].x < lt[i].x - dis || (lt[r + 1].x == lt[i].x - dis && lt[r + 1].y <= lt[i].y + d))) ++ r;
		con[lt[i].id] += r - l + 1;
		for (chkmax(pos, l); pos <= r; ++ pos) Add(lt[i].id, lt[pos].id); -- pos;
	}
}

long long ans = 0; bitset<N> vis;

void Dfs(int u) {
	if (vis[u]) return ; vis[u] = true; ans += con[u];
	for (int v : G[u]) Dfs(v);
}

int main() {

	File();

	n = read(), a = read(), b = read();

	For (i, 1, n) {
		int x = read(), y = read();
		lt[i] = (Node) {x + y, x - y, i};
	}
	dis = max(abs(lt[a].x - lt[b].x), abs(lt[a].y - lt[b].y));

	Work(dis); For (i, 1, n) swap(lt[i].x, lt[i].y); Work(dis - 1);

	Dfs(a); printf ("%lld\n", ans);

	return 0;

}

Submission Info

Judge Result