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Submission #581752

# Submission time Handle Problem Language Result Execution time Memory
581752 2022-06-23T05:43:30 Z 반딧불(#8365) Sparklers (JOI17_sparklers) C++17
0 / 100
 1 ms 312 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int n, k;
ll t;
ll arr[100002];

bool able(ll speed){
    speed*=t;
    int l = k, r = k;
    ll s = arr[k], e = arr[k];
    for(int cnt=1; cnt<n; cnt++){
        ll lDist = (s - speed) - (arr[l-1] + speed*cnt);
        ll rDist = (arr[r+1] - speed*cnt) - (e + speed);
        if(min(lDist, rDist) > 0) return false;
        if(lDist < rDist){
            l--;
            s = s - speed;
            e = min(arr[l] + speed*cnt, e+speed);
        }
        else{
            r++;
            s = max(arr[r] - speed*cnt, s-speed);
            e = e + speed;
        }
    }
    return true;
}

int main(){
    scanf("%d %d %lld", &n, &k, &t);
    for(int i=1; i<=n; i++) scanf("%lld", &arr[i]);
    arr[0] = -1e18, arr[n+1] = 1e18;
    if(arr[1] == arr[n]){
        puts("0");
        return 0;
    }

    ll L = 1, R = 1e9, ANS = 1e9;
    while(L<=R){
        ll MID = (L+R)/2;
        if(able(MID)) ANS = MID, R = MID-1;
        else L = MID+1;
    }
    printf("%lld", ANS);
}

Compilation message

sparklers.cpp: In function 'int main()':
sparklers.cpp:34:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |     scanf("%d %d %lld", &n, &k, &t);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
sparklers.cpp:35:34: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |     for(int i=1; i<=n; i++) scanf("%lld", &arr[i]);
      |                             ~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Incorrect 1 ms 312 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Incorrect 1 ms 312 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #3
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Incorrect 1 ms 312 KB Output isn't correct
8 Halted 0 ms 0 KB -