oj.uz

Submission #298613

# Submission time Handle Problem Language Result Execution time Memory
298613 2020-09-13T15:18:06 Z maximath_1 Watching (JOI13_watching) C++17
100 / 100
 196 ms 16252 KB 
#include <iostream>
#include <array>
#include <vector>
#include <algorithm>
#include <string.h>
#include <set>
#include <math.h>
#include <numeric>
#include <assert.h>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <iomanip>
#include <bitset>
#include <queue>
#include <random>
#include <chrono>
#include <deque>
#include <limits.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define ll long long
#define ld long double
#define endl "\n"
typedef tree<pair<int, int>, null_type, less<pair<int, int> >, rb_tree_tag, tree_order_statistics_node_update> OST;
typedef tree<pair<int, int>, null_type, less_equal<pair<int, int> >, rb_tree_tag, tree_order_statistics_node_update> OST_multiset;
mt19937 rng(chrono::system_clock::now().time_since_epoch().count());
const ll inf = 1e9 + 69;
const ll infll = inf * 1ll * inf;
const ld pi = 3.14159265358979323L;
const ld eps = 1e-15;
 
void setIn(string s){freopen(s.c_str(), "r", stdin);}
void setOut(string s){freopen(s.c_str(), "w", stdout);}
void unsyncIO(){cin.tie(0) -> sync_with_stdio(0);}
int setIO_count = 0;
void setIO(string s = "", bool inx = 0, bool outx = 0){
	if(!setIO_count){
		unsyncIO();
		setIO_count = 1;
	}
	if(s.size()){ //output only
		if(inx) setIn(s + ".in");
		if(outx) setOut(s + ".out");
	}
}
 
#define gc getchar//_unlocked //can't for window server
#define pc putchar//_unlocked //can't for window server
ll inp(){
	char c = gc(); bool neg = false;
	for(; c < '0'||'9' < c; c = gc())
		if(c == '-') neg=true;
	ll rs = c - '0'; c = gc();
	for(; '0' <= c && c <= '9'; c = gc())
		rs = (rs << 1) + (rs << 3) + (c - '0');
	if(neg) rs = -rs;
	return rs;
}
void pri(ll _n){
	ll N = _n, rev, count = 0;
	bool neg = false;
	if(N < 0){
		N = -N; neg = true;
	}
	rev = N;
	if(N == 0) {pc('0'); return;}
	if(neg) pc('-');
	while(rev % 10 == 0) {count ++; rev /= 10;}
	rev = 0;
	while(N != 0) {rev = (rev << 3) + (rev << 1) + N % 10; N /= 10;}
	while(rev != 0) {pc(rev % 10 + '0'); rev /= 10;}
	while(count --) pc('0');
}
 
const ll mod = 998244353;
const int N = 2005;

int n, p, q, v[N], dp[N][N];

bool check(int wt){
	memset(dp, 0, sizeof(dp));

	for(int i = 1, j = 1, k = 1; i <= n; i ++){
		while(v[i] - v[j] >= wt) j ++;
		while(v[i] - v[k] >= wt * 2) k ++;

		dp[i][0] = dp[j - 1][0] + 1;
		for(int l = 1; l <= q; l ++)
			dp[i][l] = min(dp[j - 1][l] + 1, dp[k - 1][l - 1]);
	}

	for(int i = 0; i <= q; i ++)
		if(dp[n][i] <= p) return 1;
	return 0;
}

int main(){
	setIO();

	cin >> n >> p >> q;
	for(int i = 1; i <= n; i ++)
		cin >> v[i];
	sort(v + 1, v + n + 1);

	if(n <= p + q){
		cout << 1 << endl;
		return 0;
	}

	int lf = 1, rg = 1000000000, rs = rg;
	for(int md; lf <= rg;){
		md = (lf + rg) / 2;
		if(check(md)){
			rs = md; rg = md - 1;
		}else lf = md + 1;
	}

	cout << rs << endl;

	return 0;
}

Compilation message

watching.cpp: In function 'void setIn(std::string)':
watching.cpp:35:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   35 | void setIn(string s){freopen(s.c_str(), "r", stdin);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
watching.cpp: In function 'void setOut(std::string)':
watching.cpp:36:30: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   36 | void setOut(string s){freopen(s.c_str(), "w", stdout);}
      |                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 74 ms 16128 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 72 ms 16128 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 71 ms 16128 KB Output is correct
8 Correct 68 ms 16128 KB Output is correct
9 Correct 70 ms 16128 KB Output is correct
10 Correct 69 ms 16128 KB Output is correct
11 Correct 73 ms 16128 KB Output is correct
12 Correct 72 ms 16128 KB Output is correct
13 Correct 70 ms 16128 KB Output is correct
14 Correct 67 ms 16128 KB Output is correct
15 Correct 68 ms 16128 KB Output is correct

Subtask #2
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 71 ms 16248 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 1 ms 384 KB Output is correct
7 Correct 75 ms 16128 KB Output is correct
8 Correct 127 ms 16128 KB Output is correct
9 Correct 85 ms 16128 KB Output is correct
10 Correct 79 ms 16128 KB Output is correct
11 Correct 196 ms 16128 KB Output is correct
12 Correct 138 ms 16128 KB Output is correct
13 Correct 72 ms 16128 KB Output is correct
14 Correct 72 ms 16252 KB Output is correct
15 Correct 75 ms 16128 KB Output is correct