#pragma GCC target("avx2")
#include<bits/stdc++.h>
//#include<x86intrin.h>
//#include<immintrin.h>
//#pragma GCC optimize("unroll-loops")
using namespace std;
#define ll long long
#define int ll
#define ull unsigned long long
#define ld long double
#define rep(a) rep1(i,a)
#define rep1(i,a) rep2(i,0,a)
#define rep2(i,b,a) for(int i=(b); i<((int)(a)); i++)
#define rep3(i,b,a) for(int i=(b); i>=((int)(a)); i--)
#define all(a) a.begin(),a.end()
#define pii pair<int,int>
#define pb push_back
//#define inf 1010000000
#define inf 4000000000000000000
#define eps 1e-9
#define sz(a) ((int)a.size())
#define pow2(x) (1ll<<(x))
//#define ceiling(a,b) (((a)+(b)-1)/(b))
#ifdef i_am_noob
#define bug(...) cerr << "#" << __LINE__ << ' ' << #__VA_ARGS__ << "- ", _do(__VA_ARGS__)
template<typename T> void _do(T && x) {cerr << x << endl;}
template<typename T, typename ...S> void _do(T && x, S&&...y) {cerr << x << ", "; _do(y...);}
#else
#define bug(...) 826
#endif
inline char readchar(){
const int maxn=1000000;
static char buf[maxn],*p=buf,*q=buf;
if(p==q&&(q=(p=buf)+fread(buf,1,maxn,stdin))==buf) return EOF;
else return *p++;
}
inline int readint(){
int c=readchar(),x=0,neg=0;
while((c<'0'||c>'9')&&c!='-'&&c!=EOF) c=readchar();
if(c=='-') neg=1,c=readchar();
while(c>='0'&&c<='9') x=(x<<3)+(x<<1)+(c^'0'),c=readchar();
return neg?-x:x;
}
const int Mod=1000000007,Mod2=998244353;
const int MOD=Mod;
const int maxn=100005;
//i_am_noob
//#define v8si __attribute__ (( vector_size(32) )) signed
int n,k,s,a[maxn];
pii Merge(pii x, pii y){
return {max(x.first,y.first-x.second),x.second+y.second};
}
void orzck(){
cin >> n >> k >> s;
k--;
rep(n) cin >> a[i];
int l=1,r=490e8/s;
while(l<r){
int mid=l+r>>1;
vector<int> vec1={0},vec2={0};
rep3(i,k-1,0) vec1.pb(2*s*mid-(a[i+1]-a[i]));
rep2(i,k+1,n) vec2.pb(2*s*mid-(a[i]-a[i-1]));
rep2(i,1,sz(vec1)) vec1[i]+=vec1[i-1];
rep2(i,1,sz(vec2)) vec2[i]+=vec2[i-1];
bool flag=1;
if(*min_element(all(vec1))+*max_element(all(vec2))<0) flag=0;
if(*max_element(all(vec1))+*min_element(all(vec2))<0) flag=0;
if(!flag){
l=mid+1;
continue;
}
int cur=1,maxx=0;
rep(sz(vec2)){
if(maxx+vec2[i]<0){
flag=0;
break;
}
while(cur<sz(vec1)&&vec1[cur]+vec2[i]>=0) maxx=max(maxx,vec1[cur]),cur++;
if(cur==sz(vec1)) break;
}
reverse(all(vec1));
reverse(all(vec2));
cur=1,maxx=0;
rep(sz(vec2)){
if(maxx+vec2[i]<0){
flag=0;
break;
}
while(cur<sz(vec1)&&vec1[cur]+vec2[i]>=0) maxx=max(maxx,vec1[cur]),cur++;
if(cur==sz(vec1)) break;
}
if(flag) r=mid;
else l=mid+1;
}
cout << l << "\n";
}
signed main(){
ios_base::sync_with_stdio(0),cin.tie(0);
#ifdef i_am_noob
freopen("input1.txt","r",stdin);
freopen("output1.txt","w",stdout);
freopen("output2.txt","w",stderr);
#endif
cout << fixed << setprecision(15);
orzck();
return 0;
}
Compilation message
sparklers.cpp: In function 'void orzck()':
sparklers.cpp:64:18: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
64 | int mid=l+r>>1;
| ~^~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
204 KB |
Output is correct |
2 |
Incorrect |
0 ms |
204 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |