Submission #1440942

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Source Code Expand

#include<bits/stdc++.h>
using namespace std;
const int N = 100005;

int n, a[N];
bool vis[N];

vector<vector<int> > ans;
vector<int> cp;

bool solve () {
	bool f = false;
	for(int i=1;i<=n;i++) if(a[i] != i) f = true;
	if(!f) return false;
	fill(vis+1, vis+1+n, 0);
	vector<int> st, ca;
	for(int i=1;i<=n;i++) {
		for(int j=i;!vis[j];j=a[j]) {
			st.push_back(j); vis[j] = true;
		}
		for(int i=0;i+1<st.size();i+=2) {
			ca.push_back(st[i]);
			ca.push_back(st[i+1]);
			swap(a[st[i]], a[st[i+1]]);
		}
		st.clear();
	}
	ans.push_back(ca);
	return true;
}

int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++) {
		scanf("%d",&a[i]);
		cp.push_back(a[i]);
	}
	sort(cp.begin(), cp.end());
	for(int i=1;i<=n;i++) {
		a[i] = lower_bound(cp.begin(), cp.end(), a[i]) - cp.begin() + 1;
	}
	while(solve());
	printf("%d\n",ans.size());
	for(int i=0;i<ans.size();i++) {
		printf("%d ",ans[i].size()/2);
		for(int j=0;j+1<ans[i].size();j++) {
			printf("%d ",ans[i][j]);
		}
		printf("%d\n",ans[i].back());
	}
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:44:26: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘std::vector<std::vector<int> >::size_type {aka long unsigned int}’ [-Wformat=]
  printf("%d\n",ans.size());
                          ^
./Main.cpp:46:31: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘std::vector<int>::size_type {aka long unsigned int}’ [-Wformat=]
   printf("%d ",ans[i].size()/2);
                               ^
./Main.cpp:34:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:36:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
                    ^

Judge Result