Submission #3015669

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Source Code Expand

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<string>
#include<stack>
#include<queue>
#include<vector>
#include<algorithm>
#include<iomanip>
#include<utility>
#include<set>
#include<map>
#include<unordered_set>
#include<unordered_map>
typedef long long int ll;
using namespace std;
#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define REP(i,n) for (int i=0;i<signed(n);i++)
#define EREP(i,n) for (int i=1;i<=(n);i++)
#define ALL(a) (a).begin(),(a).end()
//#define EVEL 1

#ifdef EVEL
#define DEB(X) cout << #X << ":" <<X<<" " ;
#define TF(f) f ? cout<<"true  " : cout<<"false ";
#define END cout<<"\n";
#else
#define DEB(X) {}
#define TF(f) {}
#define END {}
#endif
const int MOD = 1000000007;
const ll INF = 20000000000;
typedef std::pair<int,int> P;


	ll ans=0;
	ll N,K,G,A[500010],B[500010];
	ll sum;
	string S;
ll gcd(ll a,ll b){
    if(b==0)return a;
    return gcd(b,a%b);
}
bool F=true;
int main(){
	ios_base::sync_with_stdio(false);
	cin>>S;
	int l=0,r=S.size()-1;
	while(l<r){
		DEB(l)DEB(r)END
		if(S[l]==S[r])l++,r--;
		else if(S[l]=='x')l++,ans++;
		else if(S[r]=='x')r--,ans++;
		else{F=false;break;}
	}
	cout<<(F?ans:-1)<<endl;
}

Submission Info

Judge Result