Submission #121971

#	Time	Username	Problem	Language	Result	Execution time	Memory
121971		nvmdava	Ancient Books (IOI17_books)	C++17	Compilation error	0 ms	0 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;

bool in[1000005];
vector<pair<int, int> > cyc, tmp;
int mn, mx;
long long res;
void dfs(int i, vector<int>& p){
	if(in[i]) return;
	in[i] = 1;
	mx = max(mx, i);
	mn = min(mn, i);
	dfs(p[i], p);
}

long long minimum_walk(std::vector<int> p, int s) {
	for(int i = 0; i < p.size(); i++){
		res += abs(p[i] - i);
		if(in[i]) continue;
		mn = i;
		mx = i;
		dfs(i, p);
		if(mn != mx)tmp.push_back({mn , mx});
	}
	if(tmp.empty()) return 0;
	sort(tmp.begin(), tmp.end());
	mx = -1;
	for(auto& x : tmp){
		if(mx < x.first){
			if(!cyc.empty()){
				res += 2 * (x.first - mx);
			}
			cyc.push_back(x);
		}
		mx = max(mx, x.second);
	}
	if(s < cyc[0].first) res += 2 * (cyc[0].first - s);
	if(s > cyc.back().second) res += 2 * (s - cyc.back().second);
	return res;
}



int main() {
	int n, s;
	scanf("%d %d", &n, &s);

	vector<int> p((unsigned) n);
	for(int i = 0; i < n; i++)
		1 == scanf("%d", &p[(unsigned) i]);

	long long res = minimum_walk(p, s);
	printf("%lld\n", res);

	return 0;
}

Compilation message (stderr)

books.cpp: In function 'long long int minimum_walk(std::vector<int>, int)':
books.cpp:18:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < p.size(); i++){
                 ~~^~~~~~~~~~
books.cpp: In function 'int main()':
books.cpp:51:5: warning: value computed is not used [-Wunused-value]
   1 == scanf("%d", &p[(unsigned) i]);
   ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
books.cpp:47:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d %d", &n, &s);
  ~~~~~^~~~~~~~~~~~~~~~~
/tmp/ccha50ZU.o: In function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'
/tmp/ccrnsuRk.o:books.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status