#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
typedef pair<ll, ll> pll;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define ms memset
#define pb push_back
#define fi first
#define se second
/*Decompose the array into blocks such that:
Leftmost value of block is max in the block
the values of leftmost of each block is strictly increasing
Each swap simply decompose the block containing position n/2, n/2+1
(i.e. a "cut" between n/2 and n/2+1)
Then the blocks will be sorted based on leftmost value.
The structure of the blocks can be maintained using segtree*/
/*segtree used to find the position & maintain the blocks
sm[v] (with tl==tr) stores the number of elements in the block with leftmost value tl.
*/
struct segtree{
int sz; vi sm;
void init(int n){
sz=n; sm.assign(4*n,0);
}
void update(int v, int tl, int tr, int pos, int val){
if (tl==tr) {sm[v]=val; return;}
int tm=(tl+tr)/2;
if (pos<=tm) update(2*v,tl,tm,pos,val);
else update(2*v+1,tm+1,tr,pos,val);
sm[v]=sm[2*v]+sm[2*v+1];
}
void update(int pos, int val) {update(1,0,sz-1,pos,val);}
ii get(int v, int tl, int tr, int val){
if (tl==tr) {return {tl,val};}
int tm=(tl+tr)/2;
if (sm[2*v]<val) return get(2*v+1,tm+1,tr,val-sm[2*v]);
return get(2*v,tl,tm,val);
}
ii get(int val){return get(1,0,sz-1,val);}
};
//segtree2 is range maximum, returns index with max value.
struct segtree2{
int sz; vi mx, a;
void init(int n, vi A){
sz=n; mx.assign(4*n,-1); a=A;
}
void build(int v, int tl, int tr){
if (tl==tr){mx[v]=tl; return;}
int tm=(tl+tr)/2;
build(2*v,tl,tm); build(2*v+1,tm+1,tr);
if (a[mx[2*v]]>a[mx[2*v+1]]) mx[v]=mx[2*v];
else mx[v]=mx[2*v+1];
}
int get(int v, int tl, int tr, int l, int r){
if (tl==l && tr==r) return mx[v];
if (l>r) return -1;
int tm=(tl+tr)/2;
int L=get(2*v,tl,tm,l,min(r,tm)); int R=get(2*v+1,tm+1,tr,max(l,tm+1),r);
if (L==-1) return R;
if (R==-1) return L;
if (a[L]<a[R]) return R;
return L;
}
int get(int l, int r){return get(1,0,sz-1,l,r);}
};
//offline query, sort the query in increasing order of t-value (# swaps)
struct que{
int id, pos, t;
};
void solve(){
int n,q; cin>>n>>q;
vi a(n); FOR(i,0,n){ cin>>a[i]; a[i]--;}
segtree2 st2; st2.init(n,a); st2.build(1,0,n-1);
vi pos(n); FOR(i,0,n) pos[a[i]]=i;
vi sz(n);
vector<que> Q[n]; vi ans(q);
FOR(i,0,q){
que qr; cin>>qr.t>>qr.pos; qr.id=i; qr.pos--;
if (qr.t>=n) qr.t=n-1;
Q[qr.t].pb(qr);
}
segtree st; st.init(n);
vi used(n); // decompose the array
ROF(i,n-1,0){
if (used[i]) continue;
int L = pos[i]; int cnt=0;
while (L < n){
if (used[a[L]]) break;
cnt++; used[a[L]]=1; L++;
}
st.update(i,cnt); sz[i]=cnt;
//cout<<i<<" "<<cnt<<'\n';
}
FOR(i,0,n){
for (que qr : Q[i]){
ii val = st.get(qr.pos+1);
ans[qr.id] = a[pos[val.fi]+val.se-1];
}
ii val = st.get(n/2+1);
if (val.se == 1) continue;
// there is block containing the middle 2 positions, decompose this block.
int L=pos[val.fi]+val.se-1, R=pos[val.fi]+sz[val.fi]-1;
while(st2.get(L,R) != -1){
int mx = st2.get(L,R);
sz[a[mx]]=R-mx+1; st.update(a[mx],sz[a[mx]]);
R=mx-1;
}
sz[val.fi]=val.se-1; st.update(val.fi, sz[val.fi]);
}
FOR(i,0,q) cout<<ans[i]+1<<"\n";
}
int main(){
//MOD=MOD1;
ios::sync_with_stdio(false);
if (fopen("input.txt", "r")) {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
int TC = 1;
//cin >> TC;
FOR(i, 1, TC+1){
//cout << "Case #" << i << ": ";
solve();
}
return 0;
}
Compilation message
Main.cpp: In function 'int main()':
Main.cpp:128:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
128 | freopen("input.txt", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:129:13: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
129 | freopen("output.txt", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
205 ms |
23364 KB |
Output is correct |
2 |
Correct |
213 ms |
21656 KB |
Output is correct |
3 |
Correct |
203 ms |
21304 KB |
Output is correct |
4 |
Correct |
169 ms |
19640 KB |
Output is correct |
5 |
Correct |
193 ms |
23800 KB |
Output is correct |
6 |
Correct |
198 ms |
24892 KB |
Output is correct |
7 |
Correct |
206 ms |
25108 KB |
Output is correct |
8 |
Correct |
261 ms |
23172 KB |
Output is correct |
9 |
Correct |
188 ms |
21804 KB |
Output is correct |
10 |
Correct |
196 ms |
20736 KB |
Output is correct |
11 |
Correct |
204 ms |
21416 KB |
Output is correct |
12 |
Correct |
177 ms |
19160 KB |
Output is correct |
13 |
Correct |
185 ms |
19976 KB |
Output is correct |
14 |
Correct |
191 ms |
23756 KB |
Output is correct |
15 |
Correct |
183 ms |
20196 KB |
Output is correct |
16 |
Correct |
0 ms |
340 KB |
Output is correct |
17 |
Correct |
209 ms |
19440 KB |
Output is correct |
18 |
Correct |
162 ms |
19312 KB |
Output is correct |
19 |
Correct |
0 ms |
212 KB |
Output is correct |
20 |
Correct |
0 ms |
212 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
311 ms |
37280 KB |
Output is correct |
2 |
Correct |
284 ms |
37220 KB |
Output is correct |
3 |
Correct |
235 ms |
31916 KB |
Output is correct |
4 |
Correct |
214 ms |
32052 KB |
Output is correct |
5 |
Correct |
222 ms |
32792 KB |
Output is correct |
6 |
Correct |
206 ms |
31620 KB |
Output is correct |
7 |
Correct |
250 ms |
37108 KB |
Output is correct |
8 |
Correct |
246 ms |
35568 KB |
Output is correct |
9 |
Correct |
215 ms |
32668 KB |
Output is correct |
10 |
Correct |
227 ms |
35392 KB |
Output is correct |
11 |
Correct |
193 ms |
32448 KB |
Output is correct |
12 |
Correct |
192 ms |
31484 KB |
Output is correct |
13 |
Correct |
234 ms |
35760 KB |
Output is correct |
14 |
Correct |
196 ms |
32448 KB |
Output is correct |
15 |
Correct |
304 ms |
36352 KB |
Output is correct |
16 |
Correct |
27 ms |
15044 KB |
Output is correct |
17 |
Correct |
284 ms |
35808 KB |
Output is correct |
18 |
Correct |
171 ms |
31740 KB |
Output is correct |
19 |
Correct |
66 ms |
19208 KB |
Output is correct |
20 |
Correct |
72 ms |
18704 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
81 ms |
10932 KB |
Output is correct |
2 |
Correct |
76 ms |
10704 KB |
Output is correct |
3 |
Correct |
85 ms |
10380 KB |
Output is correct |
4 |
Correct |
62 ms |
10504 KB |
Output is correct |
5 |
Correct |
58 ms |
10700 KB |
Output is correct |
6 |
Correct |
43 ms |
10276 KB |
Output is correct |
7 |
Correct |
73 ms |
10644 KB |
Output is correct |
8 |
Correct |
51 ms |
10264 KB |
Output is correct |
9 |
Correct |
80 ms |
10492 KB |
Output is correct |
10 |
Correct |
44 ms |
10160 KB |
Output is correct |
11 |
Correct |
58 ms |
10700 KB |
Output is correct |
12 |
Correct |
43 ms |
10276 KB |
Output is correct |
13 |
Correct |
37 ms |
9968 KB |
Output is correct |
14 |
Correct |
40 ms |
10488 KB |
Output is correct |
15 |
Correct |
35 ms |
10328 KB |
Output is correct |
16 |
Correct |
19 ms |
7632 KB |
Output is correct |
17 |
Correct |
44 ms |
9520 KB |
Output is correct |
18 |
Correct |
45 ms |
9508 KB |
Output is correct |
19 |
Correct |
1 ms |
256 KB |
Output is correct |
20 |
Correct |
1 ms |
260 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
205 ms |
23364 KB |
Output is correct |
2 |
Correct |
213 ms |
21656 KB |
Output is correct |
3 |
Correct |
203 ms |
21304 KB |
Output is correct |
4 |
Correct |
169 ms |
19640 KB |
Output is correct |
5 |
Correct |
193 ms |
23800 KB |
Output is correct |
6 |
Correct |
198 ms |
24892 KB |
Output is correct |
7 |
Correct |
206 ms |
25108 KB |
Output is correct |
8 |
Correct |
261 ms |
23172 KB |
Output is correct |
9 |
Correct |
188 ms |
21804 KB |
Output is correct |
10 |
Correct |
196 ms |
20736 KB |
Output is correct |
11 |
Correct |
204 ms |
21416 KB |
Output is correct |
12 |
Correct |
177 ms |
19160 KB |
Output is correct |
13 |
Correct |
185 ms |
19976 KB |
Output is correct |
14 |
Correct |
191 ms |
23756 KB |
Output is correct |
15 |
Correct |
183 ms |
20196 KB |
Output is correct |
16 |
Correct |
0 ms |
340 KB |
Output is correct |
17 |
Correct |
209 ms |
19440 KB |
Output is correct |
18 |
Correct |
162 ms |
19312 KB |
Output is correct |
19 |
Correct |
0 ms |
212 KB |
Output is correct |
20 |
Correct |
0 ms |
212 KB |
Output is correct |
21 |
Correct |
311 ms |
37280 KB |
Output is correct |
22 |
Correct |
284 ms |
37220 KB |
Output is correct |
23 |
Correct |
235 ms |
31916 KB |
Output is correct |
24 |
Correct |
214 ms |
32052 KB |
Output is correct |
25 |
Correct |
222 ms |
32792 KB |
Output is correct |
26 |
Correct |
206 ms |
31620 KB |
Output is correct |
27 |
Correct |
250 ms |
37108 KB |
Output is correct |
28 |
Correct |
246 ms |
35568 KB |
Output is correct |
29 |
Correct |
215 ms |
32668 KB |
Output is correct |
30 |
Correct |
227 ms |
35392 KB |
Output is correct |
31 |
Correct |
193 ms |
32448 KB |
Output is correct |
32 |
Correct |
192 ms |
31484 KB |
Output is correct |
33 |
Correct |
234 ms |
35760 KB |
Output is correct |
34 |
Correct |
196 ms |
32448 KB |
Output is correct |
35 |
Correct |
304 ms |
36352 KB |
Output is correct |
36 |
Correct |
27 ms |
15044 KB |
Output is correct |
37 |
Correct |
284 ms |
35808 KB |
Output is correct |
38 |
Correct |
171 ms |
31740 KB |
Output is correct |
39 |
Correct |
66 ms |
19208 KB |
Output is correct |
40 |
Correct |
72 ms |
18704 KB |
Output is correct |
41 |
Correct |
81 ms |
10932 KB |
Output is correct |
42 |
Correct |
76 ms |
10704 KB |
Output is correct |
43 |
Correct |
85 ms |
10380 KB |
Output is correct |
44 |
Correct |
62 ms |
10504 KB |
Output is correct |
45 |
Correct |
58 ms |
10700 KB |
Output is correct |
46 |
Correct |
43 ms |
10276 KB |
Output is correct |
47 |
Correct |
73 ms |
10644 KB |
Output is correct |
48 |
Correct |
51 ms |
10264 KB |
Output is correct |
49 |
Correct |
80 ms |
10492 KB |
Output is correct |
50 |
Correct |
44 ms |
10160 KB |
Output is correct |
51 |
Correct |
58 ms |
10700 KB |
Output is correct |
52 |
Correct |
43 ms |
10276 KB |
Output is correct |
53 |
Correct |
37 ms |
9968 KB |
Output is correct |
54 |
Correct |
40 ms |
10488 KB |
Output is correct |
55 |
Correct |
35 ms |
10328 KB |
Output is correct |
56 |
Correct |
19 ms |
7632 KB |
Output is correct |
57 |
Correct |
44 ms |
9520 KB |
Output is correct |
58 |
Correct |
45 ms |
9508 KB |
Output is correct |
59 |
Correct |
1 ms |
256 KB |
Output is correct |
60 |
Correct |
1 ms |
260 KB |
Output is correct |
61 |
Correct |
738 ms |
45772 KB |
Output is correct |
62 |
Correct |
476 ms |
45328 KB |
Output is correct |
63 |
Correct |
423 ms |
43800 KB |
Output is correct |
64 |
Correct |
361 ms |
43944 KB |
Output is correct |
65 |
Correct |
459 ms |
45716 KB |
Output is correct |
66 |
Correct |
357 ms |
43652 KB |
Output is correct |
67 |
Correct |
319 ms |
43192 KB |
Output is correct |
68 |
Correct |
355 ms |
41468 KB |
Output is correct |
69 |
Correct |
359 ms |
44688 KB |
Output is correct |
70 |
Correct |
278 ms |
39792 KB |
Output is correct |
71 |
Correct |
265 ms |
42836 KB |
Output is correct |
72 |
Correct |
292 ms |
40572 KB |
Output is correct |
73 |
Correct |
301 ms |
41776 KB |
Output is correct |
74 |
Correct |
308 ms |
43972 KB |
Output is correct |
75 |
Correct |
281 ms |
41460 KB |
Output is correct |
76 |
Correct |
26 ms |
15048 KB |
Output is correct |
77 |
Correct |
315 ms |
36192 KB |
Output is correct |
78 |
Correct |
362 ms |
35968 KB |
Output is correct |
79 |
Correct |
0 ms |
212 KB |
Output is correct |
80 |
Correct |
0 ms |
212 KB |
Output is correct |