#include <bits/stdc++.h>
#define lsb(x) (x & (-x))
#define ll long long
#define ull unsigned long long
#define ld long double
// 217
// 44
using namespace std;
const int MAXN = (int) 1e6;
char str[MAXN + 1];
typedef struct Treap *T;
typedef pair <T, T> PTT;
T root, NIL;
struct Treap {
Treap *left, *right;
char ch;
int prio, sz;
Treap(char _ch) {
left = right = NIL;
ch = _ch;
prio = rand();
sz = 1;
}
};
inline void refresh(T nod) {
nod -> sz = nod -> left -> sz + nod -> right -> sz + 1;
}
T join(T a, T b) {
if(a == NIL) {
return b;
}
if(b == NIL) {
return a;
}
if(a -> prio >= b -> prio) {
a -> right = join(a -> right, b);
refresh(a);
return a;
}
b -> left = join(a, b -> left);
refresh(b);
return b;
}
PTT split(T nod, int sz) {
if(nod == NIL) {
return {NIL, NIL};
}
if(nod -> left -> sz >= sz) {
PTT aux = split(nod -> left, sz);
nod -> left = aux.second;
refresh(nod);
return {aux.first, nod};
}
if(nod -> left -> sz + 1 == sz) {
T aux = nod -> right;
nod -> right = NIL;
refresh(nod);
return {nod, aux};
}
PTT aux = split(nod -> right, sz - nod -> left -> sz - 1);
nod -> right = aux.first;
refresh(nod);
return {nod, aux.second};
}
T ins(T nod, int sz, char ch) {
PTT aux = split(nod, sz - 1);
T cur = new Treap(ch);
return join(aux.first, join(cur, aux.second));
}
T del(T nod, int sz, char &cur) {
PTT aux1 = split(nod, sz - 1);
PTT aux2 = split(aux1.second, 1);
cur = aux2.first -> ch;
return join(aux1.first, aux2.second);
}
char query(T nod, int sz) {
if(nod -> left -> sz + 1 == sz) {
return nod -> ch;
}
if(nod -> left -> sz >= sz) {
return query(nod -> left, sz);
}
return query(nod -> right, sz - nod -> left -> sz - 1);
}
int main() {
//ifstream cin("A.in");
//ofstream cout("A.out");
int i, n, m;
ios::sync_with_stdio(false);
cin.tie(0), cout.tie(0);
srand(time(NULL));
cin >> n >> m;
cin >> str + 1;
NIL = new Treap(0);
NIL -> left = NIL -> right = NIL;
NIL -> sz = NIL -> prio = 0;
root = NIL;
for(i = 1; i <= n; i++) {
root = ins(root, i, str[i]);
}
for(i = 1; i <= m; i++) {
char ch;
cin >> ch;
if(ch == 'a') {
int p1, p2;
cin >> p1 >> p2;
char cur;
del(root, p1, cur);
ins(root, p2, cur);
}
else {
int p;
cin >> p;
cout << query(root, p) << "\n";
}
}
//cin.close();
//cout.close();
return 0;
}
Compilation message
collider.cpp: In function 'int main()':
collider.cpp:106:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
cin >> str + 1;
~~~~^~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |