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Submission #624366

# Submission time Handle Problem Language Result Execution time Memory
624366 2022-08-08T04:10:02 Z zhangjishen trapezoid (balkan11_trapezoid) C++
100 / 100
 112 ms 10300 KB 
#include<bits/stdc++.h>
using namespace std;

#define pb push_back
template<typename T> bool chkmax(T &a, T b){return b > a ? a = b, 1 : 0;}
const int MAXN = 1e5 + 10, mod = 30013;

// BIT
struct BIT_max{
	int bit[MAXN * 2], siz;

	BIT_max(int n){
		siz = n;
		memset(bit, 0, sizeof(bit));
	}

	int lsb(int i){
		return i & -i;
	}

	void upd(int i, int k){
		for(; i <= siz; i += lsb(i))
			chkmax(bit[i], k);
	}

	int ask(int i){
		int ans = 0;
		for(; i; i -= lsb(i))
			chkmax(ans, bit[i]);
		return ans;
	}
};

struct BIT_sum{
	int bit[MAXN * 2], siz;

	BIT_sum(int n){
		siz = n;
		memset(bit, 0, sizeof(bit));
	}

	int lsb(int i){
		return i & -i;
	}

	void add(int i, int k){
		for(; i <= siz; i += lsb(i))
			(bit[i] += k) %= mod;
	}

	int ask(int i){
		int ans = 0;
		for(; i; i -= lsb(i))
			(ans += bit[i]) %= mod;
		return (ans + mod) % mod;
	}
};

struct Op{
	int x, y, tp, i;
	friend bool operator<(const Op& a, const Op& b){
		return a.x < b.x;
	}
};

int tot, disc[MAXN * 2];
void Disc(int n, int c[], int d[]){
	tot = 0;
	for(int i = 1; i <= n; i++)
		disc[++tot] = c[i], disc[++tot] = d[i];
	sort(disc + 1, disc + tot + 1);
	tot = unique(disc + 1, disc + tot + 1) - disc - 1;
	for(int i = 1; i <= n; i++){
		c[i] = lower_bound(disc + 1, disc + tot + 1, c[i]) - disc;
		d[i] = lower_bound(disc + 1, disc + tot + 1, d[i]) - disc;
	}
}

int dp_f(int n, int a[], int b[], int c[], int d[], int f[]){
	// sort op
	vector<Op> op;
	for(int i = 1; i <= n; i++){
		op.pb((Op){a[i], c[i], 2, i});
		op.pb((Op){b[i], d[i], 1, i});
	}
	sort(op.begin(), op.end());
	// dp f
	BIT_max y(tot);	// y[i]: max f at y = i
	for(int i = 0; i < (int)op.size(); i++){
		if(op[i].tp == 1)
			y.upd(op[i].y, f[op[i].i]);
		else f[op[i].i] = y.ask(op[i].y) + 1;
	}
	// ans
	int ans = 0;
	for(int i = 1; i <= n; i++)
		chkmax(ans, f[i]);
	return ans;
}

int dp_g(int n, int a[], int b[], int c[], int d[], int f[], int g[], int len){
	vector<int> tpz[MAXN];	// catagorize trapezoid with f = 1 ~ len
	for(int i = 1; i <= n; i++)
		tpz[f[i]].pb(i);
	// dp g
	for(int i = 0; i < (int)tpz[1].size(); i++)	// init
		g[tpz[1][i]] = 1;

	vector<Op> op;	
	BIT_sum y(tot);
	for(int k = 2; k <= len; k++){
		op.clear();
		for(int i = 0; i < (int)tpz[k - 1].size(); i++){
			int j = tpz[k - 1][i];
			op.pb((Op){b[j], d[j], 1, j});
		}
		for(int i = 0; i < (int)tpz[k].size(); i++){
			int j = tpz[k][i];
			op.pb((Op){a[j], c[j], 2, j});
		}
		sort(op.begin(), op.end());

		for(int i = 0; i < (int)op.size(); i++){
			if(op[i].tp == 1)
				y.add(op[i].y, g[op[i].i]);
			else g[op[i].i] = y.ask(op[i].y);
		}

		// undo BIT in linear time
		for(int i = 0; i < (int)op.size(); i++)
			if(op[i].tp == 1)
				y.add(op[i].y, -g[op[i].i]);
	}

	int ans = 0;
	for(int i = 1; i <= n; i++)
		if(f[i] == len)
			(ans += g[i]) %= mod;
	return ans;
}

int n, a[MAXN], b[MAXN], c[MAXN], d[MAXN], f[MAXN], g[MAXN], ans1, ans2;
int main(){
	// input
	scanf("%d", &n);
	for(int i = 1; i <= n; i++)
		scanf("%d%d%d%d", &a[i], &b[i], &c[i], &d[i]);
	// disc
	Disc(n, c, d);
	ans1 = dp_f(n, a, b, c, d, f);
	ans2 = dp_g(n, a, b, c, d, f, g, ans1);
	printf("%d %d\n", ans1, ans2);
}

Compilation message

trapezoid.cpp: In function 'int main()':
trapezoid.cpp:145:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  145 |  scanf("%d", &n);
      |  ~~~~~^~~~~~~~~~
trapezoid.cpp:147:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  147 |   scanf("%d%d%d%d", &a[i], &b[i], &c[i], &d[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
100.0 / 100.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 3412 KB Output is correct
2 Correct 2 ms 3384 KB Output is correct
3 Correct 2 ms 3412 KB Output is correct
4 Correct 3 ms 3564 KB Output is correct
5 Correct 3 ms 3668 KB Output is correct
6 Correct 4 ms 3700 KB Output is correct
7 Correct 5 ms 3780 KB Output is correct
8 Correct 7 ms 3760 KB Output is correct
9 Correct 11 ms 4184 KB Output is correct
10 Correct 23 ms 4684 KB Output is correct
11 Correct 26 ms 5200 KB Output is correct
12 Correct 52 ms 6692 KB Output is correct
13 Correct 61 ms 7528 KB Output is correct
14 Correct 75 ms 8892 KB Output is correct
15 Correct 80 ms 9036 KB Output is correct
16 Correct 87 ms 9272 KB Output is correct
17 Correct 89 ms 9596 KB Output is correct
18 Correct 93 ms 9784 KB Output is correct
19 Correct 94 ms 10044 KB Output is correct
20 Correct 112 ms 10300 KB Output is correct