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ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#356660 | #6567. Repetitive String Invention | ec1117 | TL | 8ms | 58668kb | C++14 | 4.0kb | 2024-03-18 07:13:54 | 2024-03-18 07:13:55 |
Judging History
answer
#include <bits/stdc++.h>
#include <random>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pi;
typedef vector<int> vi;
typedef vector<pi> vpi;
#define mp make_pair
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rsz resize
#define bk back()
#define pb push_back
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define For(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)
const int MOD = 1e9+7;
const int MX = 807;
const int MX2 = 407;
const ld PI = acos((ld)-1);
mt19937 rng; // or mt19937_64
template<class T> bool ckmin(T& a, const T& b) {
return b < a ? a = b, 1 : 0; }
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
cerr << h; if (sizeof...(t)) cerr << ", ";
DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif
/**
* Description: Multiply two 64-bit integers mod another if 128-bit is not available.
* modMul is equivalent to \texttt{(ul)(\_\_int128(a)*b\%mod)}.
* Works for $0\le a,b<mod<2^{63}.$
* Source: KACTL
* Verification: see "Faster Factoring"
*/
typedef unsigned long long ul;
ul modMul(ul a, ul b, const ul mod) {
ll ret = a*b-mod*(ul)((ld)a*b/mod);
return ret+((ret<0)-(ret>=(ll)mod))*mod; }
ul modPow(ul a, ul b, const ul mod) {
if (b == 0) return 1;
ul res = modPow(a,b/2,mod); res = modMul(res,res,mod);
return b&1 ? modMul(res,a,mod) : res;
}
int M[MX][MX];
int pr = 1007, pw[MX];
unordered_map<int,int> toPush[MX][MX], toPush2[MX][MX2], have[MX2], have2[MX2];
unordered_map<int,int> sameLen[MX];
//have is when later is longer end
//have2 is for shorter end
int main() {
ios_base::sync_with_stdio(0); cin.tie(0);
string S;cin>>S;
int n = sz(S);
pw[0]=1;
ll ans = 0;
FOR(i,1,n+1)
pw[i] = pw[i-1]*pr%MOD;
For(i,n) {
ll cur = 0;
FOR(j,i,n) {
cur = (cur*pr+ (S[j]-'a')+1)%MOD;
M[i][j] = cur;
}
}
ll ans2 = 0;
For(i,n) {
FOR(j,i,n) { // i to j
ans2 += sameLen[j-i+1][M[i][j]];
}
For(j,i+1) {// j to i
int len = i-j+1;
sameLen[len][M[j][i]]++;
}
}
For(i,n) {
For(j,n+1) { //j is needLen
trav(x,toPush2[i][j]) {
have2[j][x.f] += x.s;
}
trav(x,toPush[i][j]) {
have[j][x.f] += x.s;
}
}
ll cur = 0;
FOR(j,i,n) { //i st, j end
int len = j-i+1;
cur = (cur*pr+ (S[j]-'a')+1)%MOD;
for(int k=j-1;k>=0 && 2*(k-i+1)>len; k--) { // i to k
dbg(i,k,j);
int newLen = k-i+1;
int needLen = 2*newLen - len;
// ll val = v[k-i];
ll val = M[i][k];
ll fin = (val*pw[newLen]+val)%MOD;
ll want = (fin-(cur*pw[needLen])%MOD+MOD)%MOD;
dbg("D",val,fin,want,needLen);
toPush2[j+1][needLen][want]++;
}
dbg("A",j+1,len,cur);
toPush[j+1][len][cur]++;
}
cur = 0;
FOR(j,i,n) { // second part
int len = j-i+1;
cur = (cur*pr+ (S[j]-'a')+1)%MOD;
dbg("C",len,cur, have2[len][cur]);
ans += have2[len][cur];
for(int k=i+1;k<j && 2*(j-k+1)>len;k++) { // k to j
int newLen = j-k+1;
int needLen = 2*newLen - len;
ll val = M[k][j];
ll fin = (val*pw[newLen]+val)%MOD;
ll want = ((fin-cur)%MOD+MOD)*modPow(pw[len],MOD-2,MOD)%MOD;
dbg("B",val, fin, needLen,want, have[needLen][want]);
ans += have[needLen][want];
}
}
}
dbg(ans2);
cout << ans+ans2 << '\n';
}
/*
FOR(i,1,n+1) {
int cur = 0;
For(j,n) {
cur = (cur*pr + (S[j]-'a'))%MOD;
if(j>=i-1) {
M[i][cur]++;
}
}
}
FOR(i,1,n/2+1) {
//count strings of len 2i
int len = 2*i;
FOR(j,1,len) {
int k = 2*i-j;
}
}
*/
/* stuff you should look for
* int overflow, array bounds
* special cases (n=1?)
* do smth instead of nothing and stay organized
* WRITE STUFF DOWN
*/
详细
Test #1:
score: 100
Accepted
time: 8ms
memory: 58100kb
input:
aaaa
output:
9
result:
ok single line: '9'
Test #2:
score: 0
Accepted
time: 8ms
memory: 58668kb
input:
axabxbcxcdxd
output:
22
result:
ok single line: '22'
Test #3:
score: -100
Time Limit Exceeded
input:
xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx...