oj.uz

Submission #385140

# Submission time Handle Problem Language Result Execution time Memory
385140 2021-04-03T10:30:59 Z cpp219 Watching (JOI13_watching) C++14
50 / 100
 667 ms 262148 KB 
#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define fs first
#define sc second
using namespace std;
const ll N = 2e3 + 6;
const ll Log2 = 19;
const ll inf = 1e9 + 7;
typedef pair<ll,ll> LL;
vector<ll> v;
ll n,P,Q,a[N],dp[N][N],val,jump[N][2]; /// 0 if short jump    1 long jump

ll Find(ll x){
    if (x > a[n]) return n + 1;
	ll p = lower_bound(v.begin(),v.end(),x) - v.begin() + 1;
	return p;
}

ll f(ll pos,ll p){
	if (pos > n) return 0;
	if (dp[pos][p] != -1) return dp[pos][p];
	ll ans = inf;
	if (p) ans = f(jump[pos][0],p - 1);
	ans = min(ans,1 + f(jump[pos][1],p));
	return dp[pos][p] = ans;
}

bool chk(ll m){
	memset(dp,-1,sizeof(dp)); val = m;
	for (ll i = 1;i <= n;i++){
        jump[i][0] = Find(a[i] + m); jump[i][1] = Find(a[i] + 2*m);
    }
    jump[n + 1][0] = jump[n + 1][1] = n + 1;
	return f(1,P) <= Q;
}

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    #define task "tst"
    if (fopen(task".in", "r")){
        freopen(task".in", "r", stdin);
        //freopen(task".out", "w", stdout);
    }
    cin>>n>>P>>Q;
    for (ll i = 1;i <= n;i++) cin>>a[i]; sort(a + 1,a + n + 1);
    for (ll i = 1;i <= n;i++) v.push_back(a[i]);
    if (P + Q >= n){
        cout<<1; return 0;
    }
    ll l,m,h; l = 0; h = inf;
    while(l <= h){
    	m = (l + h)/2;
    	if (chk(m)) h = m - 1;
    	else l = m + 1;
	}
	cout<<l;
}

Compilation message

watching.cpp: In function 'int main()':
watching.cpp:47:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   47 |     for (ll i = 1;i <= n;i++) cin>>a[i]; sort(a + 1,a + n + 1);
      |     ^~~
watching.cpp:47:42: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   47 |     for (ll i = 1;i <= n;i++) cin>>a[i]; sort(a + 1,a + n + 1);
      |                                          ^~~~
watching.cpp:43:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   43 |         freopen(task".in", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 134 ms 31852 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 135 ms 31980 KB Output is correct
4 Correct 1 ms 512 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 2 ms 364 KB Output is correct
7 Correct 133 ms 31852 KB Output is correct
8 Correct 132 ms 31852 KB Output is correct
9 Correct 132 ms 31980 KB Output is correct
10 Correct 133 ms 31852 KB Output is correct
11 Correct 132 ms 31852 KB Output is correct
12 Correct 135 ms 31852 KB Output is correct
13 Correct 131 ms 31980 KB Output is correct
14 Correct 132 ms 31852 KB Output is correct
15 Correct 132 ms 31980 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 132 ms 31980 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 2 ms 364 KB Output is correct
6 Correct 2 ms 364 KB Output is correct
7 Correct 135 ms 32108 KB Output is correct
8 Correct 180 ms 31980 KB Output is correct
9 Correct 273 ms 31980 KB Output is correct
10 Runtime error 667 ms 262148 KB Execution killed with signal 9
11 Halted 0 ms 0 KB -