[ABC287E] Karuta
考虑二分 LCP,显然 LCP 是有单调性的。
然后维护一下哈希,用 multiset 判断存在性,就可以做到两只 。
ABC 还卡了 的单模哈希,所以赛时用了双模。
#include <iostream>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <set>
#include <map>
#include <unordered_map>
#include <queue>
#include <stack>
#include <vector>
#include <utility>
#include <cstdlib>
#include <string>
using namespace std;
#define ll long long
const int N = 5e5 + 5, INF = 2e9, MOD = 1e9 + 7, MOD2 = 998244353;
inline int read()
{
int op = 1, x = 0;
char ch = getchar();
while ((ch < '0' || ch > '9') && ch != '-') ch = getchar();
while (ch == '-')
{
op = -op;
ch = getchar();
}
while (ch >= '0' and ch <= '9')
{
x = (x << 1) + (x << 3) + (ch ^ 48);
ch = getchar();
}
return x * op;
}
inline void write(int x)
{
if (x < 0) putchar('-'), x = -x;
if (x > 9) write(x / 10);
putchar(x % 10 + '0');
}
int n, m, t, maxn = 0;
string s[N];
multiset<pair<long long, long long> > st;
vector<pair<long long, long long> > hs[N];
long long qpow(long long a, long long b)
{
long long res = 1, base = a;
while (b)
{
if (b & 1)
{
res = res * base;
res %= MOD;
}
base *= base;
base %= MOD;
b >>= 1;
}
return res;
}
long long qpow2(long long a, long long b)
{
long long res = 1, base = a;
while (b)
{
if (b & 1)
{
res = res * base;
res %= MOD2;
}
base *= base;
base %= MOD2;
b >>= 1;
}
return res;
}
int main()
{
// freopen("*.in", "r", stdin);
// freopen("*.out", "w", stdout);
ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
cin >> n;
for (int i = 1; i <= n; i++)
{
cin >> s[i];
long long ph = 0, ph2 = 0;
for (int j = 0; j < s[i].size(); j++)
{
ph += s[i][j] * qpow(26, j * 1LL) % MOD;
ph %= MOD;
ph2 += s[i][j] * qpow2(26, j * 1LL) % MOD2;
ph2 %= MOD2;
hs[i].emplace_back(make_pair(ph, ph2));
st.insert(make_pair(ph, ph2));
}
}
for (int i = 1; i <= n; i++)
{
for (auto j : hs[i])
{
st.erase(st.find(j));
}
maxn = 0;
int l = 1, r = s[i].size();
while (l <= r)
{
int mid = l + r >> 1;
auto g = hs[i][mid - 1];
if (st.find(g) != st.end())
{
maxn = mid;
l = mid + 1;
}
else r = mid - 1;
}
for (auto j : hs[i])
{
st.insert(j);
}
cout << maxn << "\n";
}
return 0;
}

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