Submission #1047336

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047336		dilanyan	Sprinklers (CEOI24_sprinklers)	C++17	100 / 100	99 ms	3372 KiB

Main

//-------------dilanyan------------\\ 
 
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<stdio.h>
using namespace std;
 
//------------------Kargpefines--------------------\\ 
 
#define ll long long
#define pb push_back
#define all(u) (u).begin(), (u).end()
#define pqueue priority_queue
#define upper upper_bound
#define lower lower_bound
#define umap unordered_map
#define uset unordered_set
 
void KarginSet(string name = "") {
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    if (name.size()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
}
 
//-------------------KarginConstants------------------\\ 
 
const ll mod = 1e9 + 7;
const ll inf = 2e9;
 
//-------------------KarginCode-----------------------\\ 
 
const int N = 100005, M = 1000005;

int n, m;

int s[N], f[N];
int dp[N];

void KarginSolve() {
    int n, m;
    cin >> n >> m;
    for (int i = 1;i <= n;i++) cin >> s[i];
    for (int i = 1;i <= m;i++) cin >> f[i];
    ll l = 0, r = 1e9, ans = -1;
    vector<pair<int, char>> from(n + 1), bfrom(n + 1);
    while(l <= r) {
        ll mid = (l + r) / 2;
        for (int i = 0;i <= n;i++) dp[i] = 0, bfrom[i] = { 0,'?' };
        for (int i = 0;i < n;i++) {
            if (dp[i] > dp[i + 1]) {
                dp[i + 1] = dp[i];
                bfrom[i + 1] = { i,'L' };
            }
            int lx = s[i + 1] - mid, rx = s[i + 1];
            if (f[dp[i] + 1] >= lx && f[dp[i] + 1] <= rx) {
                int x = upper(f + 1 + dp[i], f + 1 + m, rx) - f - 1;
                if (dp[i + 1] < x) {
                    dp[i + 1] = x;
                    bfrom[i + 1] = { i,'L' };
                }
            }
            lx = s[i + 1], rx = s[i + 1] + mid;
            if (f[dp[i] + 1] >= lx && f[dp[i] + 1] <= rx) {
                int x = upper(f + 1 + dp[i], f + 1 + m, rx) - f - 1;
                if (dp[i + 1] < x) {
                    dp[i + 1] = x;
                    bfrom[i + 1] = { i,'R' };
                }
            }
            if (i + 2 <= n) {
                int llx = s[i + 2] - mid, rrx = s[i + 2];
                if (llx < lx && (f[dp[i] + 1] >= lx && f[dp[i] + 1] <= rx) || (f[dp[i] + 1] >= llx && f[dp[i] + 1] <= rrx)) {
                    int x = upper(f + 1 + dp[i], f + 1 + m, rx) - f - 1;
                    if (dp[i + 2] < x) {
                        dp[i + 2] = x;
                        bfrom[i + 2] = { i,'?' };
                    }
                }
            }
        }
        if (dp[n] == m) {
            r = mid - 1;
            ans = mid;
            swap(from, bfrom);
        }
        else l = mid + 1;
    }
    cout << ans << '\n';
    if (ans == -1) return;
    int x = n;
    vector<char> answ(n + 1);
    while (x > 0) {
        if (from[x].second == '?') {
            answ[x] = 'L', answ[x - 1] = 'R';
            x -= 2;
        }
        else {
            answ[x] = from[x].second;
            x--;
        }
    }
    for (int i = 1;i <= n;i++) cout << answ[i];
}

int main() {
    KarginSet();
    int test = 1;
    //cin >> test;
    while (test--) {
        KarginSolve();
    }
    return 0; 
}

Compilation message (stderr)

Main.cpp:1:1: warning: multi-line comment [-Wcomment]
    1 | //-------------dilanyan------------\\
      | ^
Main.cpp:8:1: warning: multi-line comment [-Wcomment]
    8 | //------------------Kargpefines--------------------\\
      | ^
Main.cpp:27:1: warning: multi-line comment [-Wcomment]
   27 | //-------------------KarginConstants------------------\\
      | ^
Main.cpp:32:1: warning: multi-line comment [-Wcomment]
   32 | //-------------------KarginCode-----------------------\\
      | ^
Main.cpp: In function 'void KarginSolve()':
Main.cpp:74:30: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   74 |                 if (llx < lx && (f[dp[i] + 1] >= lx && f[dp[i] + 1] <= rx) || (f[dp[i] + 1] >= llx && f[dp[i] + 1] <= rrx)) {
      |                     ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp: In function 'void KarginSet(std::string)':
Main.cpp:22:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   22 |         freopen((name + ".in").c_str(), "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:23:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   23 |         freopen((name + ".out").c_str(), "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 0: 0 / 0
• Subtask 1: 3 / 3
• Subtask 2: 6 / 6
• Subtask 3: 17 / 17
• Subtask 4: 27 / 27
• Subtask 5: 47 / 47