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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#724755 | #9571. Border Jump 2 | FDUdululu | WA | 12ms | 144380kb | C++20 | 8.7kb | 2024-11-08 14:54:49 | 2024-11-08 14:54:49 |
Judging History
answer
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <ctime>
#include <iostream>
#include <vector>
using namespace std;
typedef long long ll;
const int N = 5e5 + 5; // |S|
const int M = 27; // max ASCII(s_i)
const int K = 20; // log N
char s[N];
struct SAM {
int n;
int tot = 1, last = 1, cnt = 1;
int sa[N], rk[N], ht[N];
struct Node {
int len, fa, edn;
int ch[27], nxt[27];
vector<int> tmp, son;
} node[N];
int st[N][K], lg[N];
void init(int N) {
n = N;
for (int i = 0; i <= n; i++)
sa[i] = rk[i] = ht[i] = 0;
for (int i = 0; i <= tot; i++) {
node[i].len = node[i].fa = node[i].edn = 0;
for (int j = 0; j < 27; j++)
node[i].ch[j] = node[i].nxt[j] = 0;
node[i].son.clear();
node[i].tmp.clear();
}
// clear 时先清空 node,再重置 tot 和 last
tot = last = cnt = 1;
}
int extend(int x, int c) {
int p = last, np = last = ++tot;
node[np].len = node[p].len + 1;
for (; p && (!node[p].ch[c]); p = node[p].fa)
node[p].ch[c] = np;
if (!p)
node[np].fa = 1;
else {
int q = node[p].ch[c];
if (node[q].len == node[p].len + 1)
node[np].fa = q;
else {
int nq = ++tot;
// 注意此处复制了结点 q, 若每个节点还要维护其他信息,注意清空或取舍
node[nq] = node[q];
node[nq].edn = 0;
node[nq].len = node[p].len + 1;
node[q].fa = node[np].fa = nq;
for (; p && node[p].ch[c] == q; p = node[p].fa)
node[p].ch[c] = nq;
}
}
node[np].edn = x;
// the node of this prefix
return np;
}
void dfs1(int x) {
for (auto y : node[x].tmp) {
dfs1(y);
node[x].edn = max(node[x].edn, node[y].edn);
}
}
void dfs2(int x) {
if (node[x].son.size() == 0) {
rk[node[x].edn] = cnt;
sa[cnt] = node[x].edn;
cnt++;
}
for (auto y : node[x].son)
dfs2(y);
}
void build() {
for (int i = 1; i <= tot; i++)
node[node[i].fa].tmp.push_back(i);
dfs1(1);
for (int i = 1; i <= tot; i++) {
int c = s[node[i].edn + node[node[i].fa].len] - 'a';
node[node[i].fa].nxt[c] = i;
}
for (int i = 1; i <= tot; i++) {
for (int j = 0; j < 27; j++)
if (node[i].nxt[j]) {
node[i].son.push_back(node[i].nxt[j]);
}
}
dfs2(1);
for (int i = 0; i < K; i++)
for (int j = 0; j <= n; j++)
st[i][j] = n;
get_ht();
for (int i = 2; i <= n; i++) // index starts with 2
lg[i] = lg[i >> 1] + 1;
for (int i = 1; i <= n; i++)
st[i][0] = ht[i];
for (int i = 1; i < K; i++)
for (int j = 1; j + (1 << i) - 1 <= n; j++)
st[j][i] = min(st[j][i - 1], st[j + (1 << (i - 1))][i - 1]);
}
void get_ht() { // ht[i] = lcp(sa[i], sa[i - 1])
for (int i = 1, k = 0; i <= n; i++) {
if (k)
--k;
// 多测记得防越界
// 或者 s[] 开两倍空间,清空后一半
while ((i + k <= n && sa[rk[i] - 1] + k <= n) && s[i + k] == s[sa[rk[i] - 1] + k])
k++;
// while (s[i + k] == s[sa[rk[i] - 1] + k])
// k++;
ht[rk[i]] = k;
}
}
int query(int L, int R) { // lcp(s[i,n],s[j,n])
int l, r;
l = min(L, R) + 1;
r = max(L, R);
int t = lg[r - l + 1];
return min(st[l][t], st[r - (1 << t) + 1][t]);
}
int findpre(int x, int len) {
int l = 1, r = x, mid, ans = x;
while (l <= r) {
mid = (l + r) >> 1;
if (query(mid, x) >= len) {
ans = mid;
r = mid - 1;
} else
l = mid + 1;
}
return ans;
}
int findsuf(int x, int len) {
int l = x, r = n, mid, ans = x;
while (l <= r) {
mid = (l + r) >> 1;
if (query(mid, x) >= len) {
ans = mid;
l = mid + 1;
} else
r = mid - 1;
}
return ans;
}
} sam;
struct PAM {
int n;
char s[N];
int tot = 1, last = 1;
struct Node {
int len, fa, dep;
int ch[26];
} node[N];
void init() {
for (int i = 0; i <= n; i++)
s[i] = ' ';
for (int i = 0; i <= tot; i++) {
node[i].len = node[i].fa = node[i].dep = 0;
for (int j = 0; j < 26; j++)
node[i].ch[j] = 0;
}
n = 0;
tot = last = 1;
s[0] = '$';
node[0] = {0, 1};
node[1] = {-1, 0};
}
int getfail(int x) {
while (s[n - node[x].len - 1] != s[n])
x = node[x].fa;
return x;
}
void extend(int c) {
s[++n] = (char)(c + 'a');
int p = getfail(last);
if (!node[p].ch[c]) {
int np = ++tot;
node[np].len = node[p].len + 2;
node[np].fa = node[getfail(node[p].fa)].ch[c];
node[np].dep = node[node[np].fa].dep + 1;
node[p].ch[c] = np;
}
last = node[p].ch[c];
}
} pam;
struct Node {
int v, l, r;
} t[N << 5];
int rt[N], tot;
void pushup(int p) {
t[p].v = max(t[t[p].l].v, t[t[p].r].v);
}
void build(int& p, int l, int r) {
p = ++tot;
t[p] = {0, 0, 0};
if (l == r)
return;
int mid = (l + r) >> 1;
build(t[p].l, l, mid);
build(t[p].r, mid + 1, r);
pushup(p);
}
void update(int& p, int q, int l, int r, int x, int d) {
p = ++tot;
t[p] = t[q];
if (l == r) {
t[p].v = d;
return;
}
int mid = (l + r) >> 1;
if (x <= mid)
update(t[p].l, t[q].l, l, mid, x, d);
else
update(t[p].r, t[q].r, mid + 1, r, x, d);
pushup(p);
}
int query(int p, int l, int r, int x, int y) {
if (x <= l && r <= y)
return t[p].v;
int mid = (l + r) >> 1;
int ans = 0;
if (x <= mid)
ans = max(ans, query(t[p].l, l, mid, x, y));
if (y > mid)
ans = max(ans, query(t[p].r, mid + 1, r, x, y));
return ans;
}
int pl[N], sum[N][26];
void solve(int T) {
int sd, td;
string t;
cin >> t;
int n = t.size(), m = 2 * n + 1;
t = " " + t;
for (int i = 1; i <= n; i++) {
s[i] = s[m - i + 1] = t[i];
for (int j = 0; j < 26; j++)
sum[i][j] = sum[i - 1][j];
sum[i][s[i] - 'a']++;
}
s[n + 1] = '{';
sam.init(m);
for (int i = m; i >= 1; i--)
sam.extend(i, s[i] - 'a');
sam.build();
pam.init();
for (int i = n; i >= 1; i--) {
pam.extend(s[i] - 'a');
int len = pam.node[pam.last].len;
pl[i] = len;
}
tot = 0;
build(rt[0], 1, m);
for (int i = 1; i <= m; i++) {
int x = sam.rk[i], d = i;
if (i <= n + 1)
d = 0;
update(rt[i], rt[i - 1], 1, m, x, d);
}
int ans = 0;
for (int i = 1; i <= n; i++) {
int res = 0;
int len = pl[i];
while (true) {
int l = sam.findpre(sam.rk[i], len);
int r = sam.findsuf(sam.rk[i], len);
int lim = m - (i + len) + 1;
int pos = query(rt[lim], 1, m, l, r);
if (pos == 0)
break;
pos = m - pos + 1;
len = pos - i + 1;
res++;
if (len == n)
break;
}
int w = i + ((pl[i] + 1) / 2) - 1;
int l = i, r = w, mid, pos = w, c = s[r] - 'a';
while (l <= r) {
mid = (l + r) >> 1;
if (sum[w][c] - sum[mid - 1][c] == (w - mid + 1)) {
pos = mid;
r = mid - 1;
} else
l = mid + 1;
}
pos = pos - i + 1;
res += (pos - 1);
res += pl[i] - 2 * (pos - 1) - 1;
ans = max(ans, res);
}
cout << ans << "\n";
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int T = 1;
cin >> T;
while (T--) {
solve(T);
}
return 0;
}
/*
5
aaaa
abbaabba
xy
aabaa
aabcaa
2
bvvvb
abcvvvcba
*/
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 7ms
memory: 144380kb
input:
3 aaaa abbaabba xy
output:
3 4 0
result:
ok 3 number(s): "3 4 0"
Test #2:
score: 0
Accepted
time: 3ms
memory: 143856kb
input:
15 eeee ooom bbcb yyaa ssdn wgww hrhr exer hcch qyyy lppa ocvo orxr lrjj pztv
output:
3 2 1 1 1 1 1 1 2 2 1 1 1 1 0
result:
ok 15 numbers
Test #3:
score: 0
Accepted
time: 12ms
memory: 143860kb
input:
52 eeeee oooom bbbcb yyyaa sssdn wwgww hhrhr eexer hhcch qqyyy llppa oocvo oorxr llrjj ppztv tnttt vnvvn hthhp jzjzj nrnrr gqgqt uruyu cdchd djdhh ktkfy piipp zaaza uffuq bvvvb hkkkk pcccj qccpq wqqaq appgg cxxvg ewfee peupe odfof kdpkh zotoz yzkzz irtrt vxyxi dlood akrrk nsbbb rdjjc bfexb uxsex ise...
output:
4 3 2 2 2 2 1 1 2 2 1 1 1 1 1 2 2 1 2 1 1 1 1 1 1 2 2 2 3 3 2 1 1 1 1 1 1 1 1 2 1 1 1 1 2 2 1 1 1 1 1 0
result:
ok 52 numbers
Test #4:
score: -100
Wrong Answer
time: 7ms
memory: 143204kb
input:
203 eeeeee ooooom bbbbcb yyyyaa ssssdn wwwgww hhhrhr eeexer hhhcch qqqyyy lllppa ooocvo ooorxr lllrjj pppztv ttnttt vvnvvn hhthhp jjzjzj nnrnrr ggqgqt uuruyu ccdchd ddjdhh kktkfy ppiipp zzaaza uuffuq bbvvvb hhkkkk ppcccj qqccpq wwqqaq aappgg ccxxvg eewfee ppeupe oodfof kkdpkh zzotoz yyzkzz iirtrt vv...
output:
5 4 3 3 3 2 2 2 2 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 3 2 2 3 3 2 1 1 1 1 2 1 1 1 2 1 1 1 1 2 2 1 1 1 1 1 1 3 3 2 3 2 2 1 1 1 1 2 2 2 2 2 1 1 1 1 1 1 2 1 1 1 1 1 1 2 1 2 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 3 4 4 3 2 2 2 2 1 1 1 1 1 2 1 1 1 2 2 1 1 1 1 1 1 2 1 2 1 2 1 1 1 1 2 1 1 1 1 1 1 1 2 2 2 2 1 2 2 ...
result:
wrong answer 131st numbers differ - expected: '1', found: '2'