Submission #851333

#	Time	Username	Problem	Language	Result	Execution time	Memory
851333		ntkphong	Wiring (IOI17_wiring)	C++14	100 / 100	44 ms	12496 KiB

wiring

#include "wiring.h"
#include <bits/stdc++.h>
using namespace std;

const long long INF = 1e18;
const int mxN = 2e5 + 10;
long long dp[mxN][2];

long long min_total_length(vector<int> r, vector<int> b) {
    
    int n = r.size() + b.size();
    vector<pair<long long, int>> arr(n + 5);
    vector<long long> prefix(n + 1, 0);
    vector<int> L, R;
    
    for(int i = 0; i < r.size(); i ++) arr[i + 1] = {r[i], 0};
    for(int i = 0; i < b.size(); i ++) arr[r.size() + i + 1] = {b[i], 1};
    
    sort(arr.begin() + 1, arr.begin() + n + 1);
    
    for(int i = 1; i <= n; i ++) 
        prefix[i] = prefix[i - 1] + arr[i].first;
    
    auto get = [&](int l, int r) {
        return prefix[r] - prefix[l - 1];
    };
    
    for(int i = 1, j = 1; i <= n; i = j + 1) {
        for(j = i; j + 1 <= n && arr[j + 1].second == arr[i].second; ) j ++ ;
        
        L.push_back(i);
        R.push_back(j);
    }
    
    arr[0] = {- INF, 0};
    arr[n + 1] = {INF, 0};
    
    for(int i = 1; i <= n; i ++) {
        dp[i][0] = dp[i][1] = INF;
    }
    
    for(int i = 0; i < L.size(); i ++) {

        for(int j = L[i]; j <= R[i]; j ++) {
            
            if(j == L[i]) {
                dp[j][0] = min({dp[j][0], 
                                dp[j - 1][0] + arr[j].first - arr[L[i] - 1].first,
                                dp[j - 1][1] + arr[j].first - arr[L[i] - 1].first});
            } else 
                dp[j][0] = min(dp[j][0], dp[j - 1][0] + arr[j].first - arr[L[i] - 1].first);
            
            dp[j][1] = min({dp[j][1], 
                            dp[j - 1][0] + arr[R[i] + 1].first - arr[j].first,
                            dp[j - 1][1] + arr[R[i] + 1].first - arr[j].first});
        }
        
        if(i + 1 < L.size()) {
            for(int j = L[i]; j <= R[i]; j ++) {
                int k = R[i] - j + 1;
                
                if(R[i + 1] - L[i + 1] + 1 < k) continue ;
                dp[R[i] + k][0] = min({dp[R[i] + k][0], 
                                       dp[j - 1][0] + get(R[i] + 1, R[i] + k) - get(j, R[i]),
                                       dp[j - 1][1] + get(R[i] + 1, R[i] + k) - get(j, R[i])});
            }
        }
    }
    
    return dp[n][0];
}

Compilation message (stderr)

wiring.cpp: In function 'long long int min_total_length(std::vector<int>, std::vector<int>)':
wiring.cpp:16:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 |     for(int i = 0; i < r.size(); i ++) arr[i + 1] = {r[i], 0};
      |                    ~~^~~~~~~~~~
wiring.cpp:17:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     for(int i = 0; i < b.size(); i ++) arr[r.size() + i + 1] = {b[i], 1};
      |                    ~~^~~~~~~~~~
wiring.cpp:42:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |     for(int i = 0; i < L.size(); i ++) {
      |                    ~~^~~~~~~~~~
wiring.cpp:58:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |         if(i + 1 < L.size()) {
      |            ~~~~~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 13 / 13
• Subtask 3: 10 / 10
• Subtask 4: 25 / 25
• Subtask 5: 45 / 45