| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 124471 |
2019-07-03T11:44:05 Z |
RockyB |
Sorting (IOI15_sorting) |
C++17 |
|
5 ms |
504 KB |
/// In The Name Of God
#include "sorting.h"
#include <bits/stdc++.h>
#define f first
#define s second
#define pb push_back
#define pp pop_back
#define mp make_pair
#define sz(x) (int)x.size()
#define sqr(x) ((x) * 1ll * (x))
#define all(x) x.begin(), x.end()
#define rep(i, l, r) for (int i = (l); i < (r); i++)
#define per(i, l, r) for (int i = (l); i >= (r); i--)
#define Kazakhstan ios_base :: sync_with_stdio(0), cin.tie(0), cout.tie(0);
#define nl '\n'
#define ioi exit(0);
const int MAXN = (int)2e5 + 7;
using namespace std;
int n, m;
int a[MAXN], b[MAXN], x[MAXN], y[MAXN];
bool check(int len) {
rep(i, 0, n) {
b[i] = a[i];
}
rep(i, 0, min(len, m)) {
swap(b[x[i]], b[y[i]]);
}
int cnt = 0;
rep(i, 0, n) {
if (b[i] != i) {
++cnt;
swap(b[i], b[b[i]]);
}
}
if (cnt > len) return 0;
return 1;
}
int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
{
n = N;
m = M;
rep(i, 0, n) {
a[i] = S[i];
}
rep(i, 0, m) {
x[i] = X[i];
y[i] = Y[i];
}
} // copying
int l = 1, r = n * 2, res = -1;
while (l <= r) {
int mid = (l + r) >> 1;
if (check(mid)) res = mid, r = mid - 1;
else l = mid + 1;
}
assert(res != -1);
// opt len found
rep(i, 0, n) {
b[i] = a[i];
}
rep(i, 0, min(m, res)) {
swap(b[x[i]], b[y[i]]);
}
vector <int> st;
int go[n];
rep(i, 0, n) {
go[b[i]] = i;
}
rep(i, 0, n) {
if (b[i] != i) {
st.pb(b[i]);
//swap(b[i], b[b[i]]);
}
}
int ptr = 0;
if (!sz(st)) {
ptr = 1;
P[ptr] = X[ptr];
Q[ptr] = Y[ptr];
}
swap(a[X[ptr]], a[Y[ptr]]);
for (auto x : st) {
if (go[x] == x) {
//cerr << "BAD -> " << x << nl;
P[ptr] = 0;
Q[ptr] = 0;
/*
cerr << " -> " << x << nl;
rep(i, 0, n) cerr << a[i] << ' ';
cerr << nl;
rep(i, 0, n) cerr << go[i] << ' ';
cerr << nl << nl;*/
continue;
}
int p1 = find(a, a + n, x) - a;
rep(i, 0, n) {
if (go[i] == x) {
int p2 = find(a, a + n, i) - a;
P[ptr] = p1;
Q[ptr] = p2;
swap(go[x], go[i]);
swap(a[p1], a[p2]);
ptr++;
if (ptr < m) {
swap(a[X[ptr]], a[Y[ptr]]);
///// don't use/// swap(go[a[X[ptr]]], go[a[Y[ptr]]]);
}
break;
}
}
/*
cerr << " -> " << x << nl;
rep(i, 0, n) cerr << a[i] << ' ';
cerr << nl;
rep(i, 0, n) cerr << go[i] << ' ';
cerr << nl << nl;
*/
}
/*
rep(i, 0, n) cerr << a[i] << ' ';
cerr << nl;*/
return res;
}
#ifdef IOI2018
namespace gen {
int get(int x, bool ok = 1) {
}
void gen() {
int N, M;
N = rand() % 5 + 1;
int *S = (int*)malloc(sizeof(int) * (unsigned int)N);
for (int i = 0; i < N; ++i)
S[i] = i;
random_shuffle(S, S + N);
printf ("%d\n", N);
int A[N];
for (int i = 0; i < N; i++) {
A[i] = S[i];
printf ("%d ", A[i]);
}
printf ("\n");
M = rand() % 5 + 1;
printf ("%d\n", M);
int *X = (int*)malloc(sizeof(int) * (unsigned int)M), *Y = (int*)malloc(sizeof(int) * (unsigned int)M);
for (int i = 0; i < M; ++i) {
X[i] = rand() % N;
Y[i] = rand() % N;
printf ("%d %d\n", X[i], Y[i]);
}
int *P = (int*)malloc(sizeof(int) * (unsigned int)M), *Q = (int*)malloc(sizeof(int) * (unsigned int)M);
int ans = findSwapPairs(N, S, M, X, Y, P, Q);
printf("%d\n", ans);
assert(ans <= 30 * N);
for (int i = 0; i < ans; ++i) {
swap(A[X[i]], A[Y[i]]);
swap(A[P[i]], A[Q[i]]);
}
for (int i = 0; i < N; i++) {
assert(A[i] == i);
printf("%d ", A[i]);
}
}
}
int main() {
rep(i, 1, 100) {
printf ("Case: %d\n", i);
srand(i);
gen :: gen();
printf ("\n");
}
}
#endif
Compilation message
sorting.cpp: In function 'int findSwapPairs(int, int*, int, int*, int*, int*, int*)':
sorting.cpp:95:12: warning: declaration of 'x' shadows a global declaration [-Wshadow]
for (auto x : st) {
^
sorting.cpp:30:23: note: shadowed declaration is here
int a[MAXN], b[MAXN], x[MAXN], y[MAXN];
^
sorting.cpp:113:30: warning: conversion to 'int' from 'long int' may alter its value [-Wconversion]
int p1 = find(a, a + n, x) - a;
~~~~~~~~~~~~~~~~~~^~~
sorting.cpp:117:32: warning: conversion to 'int' from 'long int' may alter its value [-Wconversion]
int p2 = find(a, a + n, i) - a;
~~~~~~~~~~~~~~~~~~^~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
2 ms |
376 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
504 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
504 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
