Submission #704905

#	Time	Username	Problem	Language	Result	Execution time	Memory
704905		RandomLB	Watching (JOI13_watching)	C++17	50 / 100	16 ms	4860 KiB

watching

#include <bits/stdc++.h>
#include <iomanip>
using namespace std;
typedef long long ll;
typedef long double ld;
#define pb push_back
#define siz(x) (int)x.size()
#define ms(x, a) memset(x, a, sizeof(x))
#define deb(...) logger(#__VA_ARGS__, __VA_ARGS__)
template<typename ...Args>
void logger(string vars, Args&&... values){
    cout << vars << " = ";
    string delim = "";
    (...,(cout << delim << values, delim = ", "));
    cout << endl;
}
const int INF = 0x3f3f3f3f;
//==================================
const int MAX = 105;
int arr[MAX], dp[MAX][MAX][MAX], n, p, q;

inline int bs(int i, int x){
    int l = 0, r = i;
    while (l+1 < r){
        int m = l+(r-l)/2;
        if (arr[i]-arr[m]+1 <= x) r = m; else l = m;
    }
    return r;
}

bool good(int w){
    int a = p, b = q, curr = -INF;
    ms(dp, 0); for (int i = 0; i <= p; i++) for (int j = 0; j <= q; j++) dp[0][i][j] = 1;
    for (int i = 1; i <= n; i++){
        int x = bs(i, w)-1, y = bs(i, 2*w)-1;
        for (int j = 0; j <= p; j++){
            for (int k = 0; k <= q; k++){
                if (j) dp[i][j][k] |= dp[x][j-1][k];
                if (k) dp[i][j][k] |= dp[y][j][k-1];
            }
        }
    }
    return dp[n][p][q];
}

int main() {
	cin.tie(0)->sync_with_stdio(0);
	cin >> n >> p >> q;
    if (p+q >= n){ cout << 1 << "\n"; return 0; }
    for (int i = 1; i <= n; i++) cin >> arr[i];
    sort(arr+1, arr+n+1);
    int l = 1, r = INF;
    while (l+1 < r){
        int m = l+(r-l)/2;
        (good(m)? r : l) = m;
    }
    cout << r << "\n";
}

Compilation message (stderr)

watching.cpp: In function 'bool good(int)':
watching.cpp:32:9: warning: unused variable 'a' [-Wunused-variable]
   32 |     int a = p, b = q, curr = -INF;
      |         ^
watching.cpp:32:16: warning: unused variable 'b' [-Wunused-variable]
   32 |     int a = p, b = q, curr = -INF;
      |                ^
watching.cpp:32:23: warning: unused variable 'curr' [-Wunused-variable]
   32 |     int a = p, b = q, curr = -INF;
      |                       ^~~~

• Subtask 1: 50 / 50
• Subtask 2: 0 / 50