oj.uz

Submission #384875

# Submission time Handle Problem Language Result Execution time Memory
384875 2021-04-02T14:32:04 Z cpp219 Watching (JOI13_watching) C++14
50 / 100
 1000 ms 33824 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;
unordered_map<ll,ll> mp;

ll Find(ll x){
	if (mp.count(x)) return mp[x];
	ll p = lower_bound(v.begin(),v.end(),x) - v.begin() + 1; mp[x] = p;
	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,nxt1 = Find(a[pos] + val),nxt2 = Find(a[pos] + val*2);
	if (p) ans = f(nxt1,p - 1);
	ans = min(ans,1 + f(nxt2,p));
	return dp[pos][p] = ans;
}

bool chk(ll m){
	memset(dp,-1,sizeof(dp)); val = m;
	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]); v.push_back(inf);
    if (P + Q >= n) return cout<<1,0;
    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:44:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   44 |     for (ll i = 1;i <= n;i++) cin>>a[i]; sort(a + 1,a + n + 1);
      |     ^~~
watching.cpp:44:42: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   44 |     for (ll i = 1;i <= n;i++) cin>>a[i]; sort(a + 1,a + n + 1);
      |                                          ^~~~
watching.cpp:45:5: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   45 |     for (ll i = 1;i <= n;i++) v.push_back(a[i]); v.push_back(inf);
      |     ^~~
watching.cpp:45:50: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   45 |     for (ll i = 1;i <= n;i++) v.push_back(a[i]); v.push_back(inf);
      |                                                  ^
watching.cpp:40:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   40 |         freopen(task".in", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
50.0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 138 ms 31852 KB Output is correct
2 Correct 2 ms 364 KB Output is correct
3 Correct 142 ms 31852 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 2 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 147 ms 31852 KB Output is correct
8 Correct 142 ms 31980 KB Output is correct
9 Correct 145 ms 31980 KB Output is correct
10 Correct 143 ms 31980 KB Output is correct
11 Correct 147 ms 31980 KB Output is correct
12 Correct 149 ms 31980 KB Output is correct
13 Correct 152 ms 32108 KB Output is correct
14 Correct 138 ms 31852 KB Output is correct
15 Correct 139 ms 31932 KB Output is correct

Subtask #2
0 / 50.0

# Verdict Execution time Memory Grader output
1 Correct 147 ms 31832 KB Output is correct
2 Correct 2 ms 364 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 2 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 146 ms 32236 KB Output is correct
8 Correct 417 ms 33776 KB Output is correct
9 Execution timed out 1072 ms 33824 KB Time limit exceeded
10 Halted 0 ms 0 KB -