oj.uz

Submission #1080616

# Submission time Handle Problem Language Result Execution time Memory
1080616 2024-08-29T11:39:41 Z isaachew Sparklers (JOI17_sparklers) C++17
0 / 100
 1 ms 348 KB 
#include <bits/stdc++.h>
/*
 The sparkler should move in both directions from the initial person after it is lit
 
 If two people meet, they should do so as soon as possible, otherwise it wouldn't make a difference
 
 A path actually depends on the sum of distances of the first and last people from the person with the sparkler
 
 */
int main(){
    std::ios::sync_with_stdio(0);
    std::cin.tie(0);
    long long n,k,t;
    std::cin>>n>>k>>t;
    k--;
    std::vector<int> places;
    for(int i=0;i<n;i++){
        int a;
        std::cin>>a;
        places.push_back(a);
    }
    
    long long lower=-1,upper=1e9;//min distance a sparkler can burn for
    while(lower+1<upper){
        long long mid=(lower+upper)/2;
        //std::cout<<mid<<'\n';
        std::vector<std::pair<long long,long long>> toleft,toright;//cost, profit
        long long curmin=0;
        long long cursum=0;
        for(int i=k-1;i>=0;i--){
            //std::cout<<i+1<<"?"<<i<<'\n';
            cursum-=(places[i+1]-places[i]);
            curmin=std::min(cursum,curmin);
            cursum+=mid;
            if(cursum>0){
                toleft.push_back({-curmin,cursum});
                cursum=0;curmin=0;
            }
        }
        std::pair<long long,long long> leftex={-curmin,-cursum};//cursum <= 0
        //std::cout<<"yes\n";
        curmin=0;cursum=0;
        for(int i=k;i<n-1;i++){
            //std::cout<<i+1<<"?"<<i<<'\n';
            cursum-=(places[i+1]-places[i]);
            curmin=std::min(cursum,curmin);
            cursum+=mid;
            if(cursum>0){
                toright.push_back({-curmin,cursum});
                cursum=0;curmin=0;
            }
        }
        std::pair<long long,long long> rightex={-curmin,-cursum};
        //std::cout<<leftex.first<<' '<<leftex.second<<'\n';
        long long lp=0,rp=0,cur=mid;
        while(lp<toleft.size()||rp<toright.size()){
            //std::cout<<lp<<' '<<rp<<"lprp\n";
            if(lp<toleft.size()&&cur>=toleft[lp].first){
                cur+=toleft[lp].second;
                lp++;
            }else if(rp<toright.size()&&cur>=toright[rp].first){
                cur+=toright[rp].second;
                rp++;
            }else{
                cur=-1;
                break;
            }
        }
        if(cur>=std::min(std::max(leftex.first,leftex.second+rightex.first),std::max(leftex.first+rightex.second,rightex.first))){
            upper=mid;
        }else{
            lower=mid;
        }
    }
    //upper/=2;//towards each other
    std::cout<<(upper+2*t-1)/(2*t)<<'\n';
}

Compilation message

sparklers.cpp: In function 'int main()':
sparklers.cpp:56:17: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |         while(lp<toleft.size()||rp<toright.size()){
      |               ~~^~~~~~~~~~~~~~
sparklers.cpp:56:35: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   56 |         while(lp<toleft.size()||rp<toright.size()){
      |                                 ~~^~~~~~~~~~~~~~~
sparklers.cpp:58:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   58 |             if(lp<toleft.size()&&cur>=toleft[lp].first){
      |                ~~^~~~~~~~~~~~~~
sparklers.cpp:61:24: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   61 |             }else if(rp<toright.size()&&cur>=toright[rp].first){
      |                      ~~^~~~~~~~~~~~~~~

Subtask #1
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 344 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Incorrect 1 ms 348 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 344 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Incorrect 1 ms 348 KB Output isn't correct
13 Halted 0 ms 0 KB -

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 1 ms 344 KB Output is correct
6 Correct 0 ms 348 KB Output is correct
7 Correct 0 ms 348 KB Output is correct
8 Correct 0 ms 344 KB Output is correct
9 Correct 0 ms 348 KB Output is correct
10 Correct 1 ms 348 KB Output is correct
11 Correct 0 ms 348 KB Output is correct
12 Incorrect 1 ms 348 KB Output isn't correct
13 Halted 0 ms 0 KB -