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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#20997 | #2492. Hash Function | Macesuted | WA | 14ms | 3712kb | C++14 | 4.2kb | 2022-02-23 16:32:01 | 2022-05-03 12:11:20 |
Judging History
answer
/**
* @file 2492.cpp
* @author Macesuted ([email protected])
* @date 2022-02-23
*
* @copyright Copyright (c) 2022
* @brief
* Time Limit: 3S Memory Limit: 64M
*
*/
#include <bits/stdc++.h>
using namespace std;
#define MP make_pair
#define MT make_tuple
namespace io {
#define SIZE (1 << 20)
char ibuf[SIZE], *iS, *iT, obuf[SIZE], *oS = obuf, *oT = oS + SIZE - 1, c, qu[55];
int f, qr;
inline void flush(void) { return fwrite(obuf, 1, oS - obuf, stdout), oS = obuf, void(); }
inline char getch(void) {
return (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin), (iS == iT ? EOF : *iS++)) : *iS++);
}
void putch(char x) {
*oS++ = x;
if (oS == oT) flush();
return;
}
string getstr(void) {
string s = "";
char c = getch();
while (c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == EOF) c = getch();
while (!(c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == EOF)) s.push_back(c), c = getch();
return s;
}
void putstr(string str, int begin = 0, int end = -1) {
if (end == -1) end = str.size();
for (int i = begin; i < end; i++) putch(str[i]);
return;
}
template <typename T>
T read() {
T x = 0;
for (f = 1, c = getch(); c < '0' || c > '9'; c = getch())
if (c == '-') f = -1;
for (x = 0; c <= '9' && c >= '0'; c = getch()) x = x * 10 + (c & 15);
return x * f;
}
template <typename T>
void write(const T& t) {
T x = t;
if (!x) putch('0');
if (x < 0) putch('-'), x = -x;
while (x) qu[++qr] = x % 10 + '0', x /= 10;
while (qr) putch(qu[qr--]);
return;
}
struct Flusher_ {
~Flusher_() { flush(); }
} io_flusher_;
} // namespace io
using io::getch;
using io::getstr;
using io::putch;
using io::putstr;
using io::read;
using io::write;
bool mem1;
#define maxn 17
int n;
long long maxS;
vector<int> S1, S2, S3;
map<long long, long long> record;
long long get(int p, int n) { return (1LL << p) | ((p & 1) ? (1LL << (p >> 1)) : (1LL << (2 * n - 1 - (p >> 1)))); }
long long R(long long S) { return (S >> 1) | ((S & 1) << (2 * n - 1)); }
long long calcB(long long A) {
long long B = 0;
for (int t = 0; t < n; t++) B |= ((A >> t & 1) ^ (A >> (2 * t + 1) & 1)) << t;
for (int t = n; t < 2 * n; t++) B |= ((A >> t & 1) ^ (A >> (4 * n - 2 * t - 2) & 1)) << t;
return B;
}
void solve(void) {
n = read<int>();
long long H = read<long long>(), mod = (1LL << (2 * n - 1)) - 1;
maxS = (1LL << (2 * n)) - 1;
long long max1S = ((1LL << n) - 1) << n, max2S = (1LL << n) - 1;
for (int i = 0; i < 2 * n; i++) {
long long S = get(i, n);
S = S ^ R(S);
vector<int> pos;
for (int j = 0; j < 2 * n; j++)
if (S >> j & 1) pos.push_back(j);
if (pos.back() < n)
S1.push_back(i);
else if (pos.front() >= n)
S2.push_back(i);
else
S3.push_back(i);
}
int S1z = S1.size(), S2z = S2.size(), S3z = S3.size();
for (int i = 0; i < (1 << S3z); i++) {
long long A_ = 0;
for (int t = 0; t < S3z; t++) A_ |= (i >> t & 1) << S3[t];
for (int j = 0; j < (1 << S1z); j++) {
long long A = A_;
for (int t = 0; t < S1z; t++) A |= (j >> t & 1) << S1[t];
long long B = calcB(A), C = B ^ R(B);
A &= max1S, C &= max1S;
record[(H + mod - (239 * A + 153 * C) % mod) % mod] = A;
}
for (int j = 0; j < (1 << S2z); j++) {
long long A = A_;
for (int t = 0; t < S2z; t++) A |= (j >> t & 1) << S2[t];
long long B = calcB(A), C = B ^ R(B);
A &= max2S, C &= max2S;
auto p = record.find((239 * A + 153 * C) % mod);
if (p != record.end()) return write(p->second | A), putch('\n');
}
record.clear();
}
return putstr("No Solution!\n");
}
bool mem2;
int main() {
#ifdef MACESUTED
cerr << "Memory: " << abs(&mem1 - &mem2) / 1024. / 1024. << "MB" << endl;
#endif
int _ = 1;
while (_--) solve();
#ifdef MACESUTED
cerr << "Time: " << clock() * 1000. / CLOCKS_PER_SEC << "ms" << endl;
#endif
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 1ms
memory: 3700kb
input:
4 83
output:
112
result:
ok good solution
Test #2:
score: -100
Wrong Answer
time: 14ms
memory: 3712kb
input:
10 497091
output:
No Solution!
result:
wrong output format Expected integer, but "No" found