#include "books.h"
#include <bits/stdc++.h>
using i64 = long long;
void chmax(i64 &a, i64 b) {
if (a < b) a = b;
}
long long minimum_walk(std::vector<int> p, int s) {
const int n = (int)p.size();
std::vector<std::vector<int>> cycles;
std::vector<i64> cycleCost;
std::vector<bool> used(n);
for (int i = 0; i < n; ++i) {
if (used[i]) continue;
int now = i;
std::vector<int> cycle;
i64 cost = 0;
do {
cycle.push_back(now);
used[now] = true;
const int nx = p[now];
cost += std::abs(nx - now);
now = nx;
} while (now != i);
if (cycle.size() == 1) {
continue;
}
cycles.push_back(std::move(cycle));
cycleCost.push_back(cost);
}
const int M = (int)cycles.size();
i64 x = 0;
for (const auto &vec : cycles) {
chmax(x, *std::min_element(vec.begin(), vec.end()));
}
const i64 costSum = std::accumulate(cycleCost.begin(), cycleCost.end(), 0ll);
return costSum + 2 * x;
}
using namespace std;
int main() {
int n, s;
assert(2 == scanf("%d %d", &n, &s));
vector<int> p((unsigned)n);
for (int i = 0; i < n; i++) assert(1 == scanf("%d", &p[(unsigned)i]));
long long res = minimum_walk(p, s);
printf("%lld\n", res);
return 0;
}
Compilation message
books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:33:15: warning: unused variable 'M' [-Wunused-variable]
33 | const int M = (int)cycles.size();
| ^
/usr/bin/ld: /tmp/cc8c1wz2.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cccLYC62.o:books.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
