Submission #1287831

#	Time	Username	Problem	Language	Result	Execution time	Memory
1287831		muhammad-mutahir	Line Town (CCO23_day1problem3)	C++20	0 / 25	1 ms	572 KiB

Main

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

#define print(l) for(auto i:l) cout<<i<<" ";cout<<endl;
#define input(t,l,n) vector<t>l(n);for(int i = 0;i<n;i++)cin>>l[i];
#define int long long
#define pb push_back
#define ordered_set tree<int, null_type,less<int>, rb_tree_tag,tree_order_statistics_node_update> 
#define all(l) l.begin(),l.end()
#define pii pair<int,int>
#define fi first
#define se second

const int M = 1e9+7;
const int inf = 1e18;


int bp(int x, int y, int p){
    int res = 1;
    x = x % p;
    while (y > 0) {
 
        if (y & 1)
            res = (res * x) % p;
        y = y >> 1;
        x = (x * x) % p;
    }
    return res;
}
 
int MI(int n, int p){
    return bp(n, p - 2, p);
}
int mul(int x,int y, int p){
    return x * 1ull * y % p;
}
int di(int x,int y, int p){
    return mul(x, MI(y, p), p);
}


int n , m , k , q;

void solve(int testcase_number){
    cin>>n;
    input(int,l,n);
    while(l.back() == 1){
    	l.pop_back();
    }
    reverse(all(l));
    while(l.back() == -1){
    	l.pop_back();
    }
    
    reverse(all(l));
    n = l.size();
    // print(l);
    vector<vector<int>>comps;
    int f = l[0];
    int i = 0;
    vector<int>assi(n+1,-1);
    vector<int>t;
    while(i<n){
    	while(l[i] == f){
    		t.pb(l[i]);
    		assi[i] = comps.size();
    		i++;
    	}
    	f = l[i];
    	comps.pb(t);
    	t = {};
    }
    n = comps.size();
    // for(auto i:comps){
    	// cout<<i[0]<<" ";
    // }
    // cout<<endl;
    // for(auto i:comps){
    	// cout<<i.size()<<" ";
    // }
    // cout<<endl;
    vector<int>pre(n+1,0);
    vector<int>suff(n+1,0);
    for(int i = 0;i<n;i++){
    	if(comps[i].size()%2 == 1 and comps[i][0] == 1){
    		pre[i] = 1;
    	}
    	if(i-1>=0){
    		pre[i]|=pre[i-1];
    	}
    }
    for(int i = n-1;i>=0;i--){
    	if(comps[i].size()%2 == 1 and comps[i][0] == -1){
    		suff[i] = 1;
    	}
    	if(i+1<n){
    		suff[i]|=suff[i+1];
    	}
    }
    int sum = 0;
    for(auto i:comps){
    	if(i[0] == -1){
    		if(i.size()%2 == 0) sum+=i.size()/2;
    	}
    }
    int ans = 1e18;
    int sum2 =0 ;
    for(int i = 0;i<n;i++){
    	// cout<<sum2<<" "<<sum<<endl;
    	if(pre[i] == 0 and suff[i] == 0){
    		
    		ans = min(ans,sum+sum2);
    		// cout<<ans<<" ";
    	}
    	if(pre[i] == 0 and comps[i][0] == 1){
    		sum2+=comps[i].size()/2;
    	}
    	if(suff[i] == 0 and comps[i][0] == -1){
    		sum-=comps[i].size()/2;
    	}
    }
    if(ans == 1e18){
    	cout<<-1<<endl;
    	return;
    }
    cout<<ans<<endl;
    // print(pre);
    // print(suff);
    
    // for(int i = 0;i<n;i++){
//     	
    // }
    // int ne = 1;
    // int po = 1;
    // int toup = 1;
    // int ans1 = 0;
    // int fne = 0;
    // int ans2 = 0;
    // for(auto i:comps){
    	// // print(i);
    	// if(i[0] == -1){
    		// if(i.size()%2 !=0){
    			// ne = 0;
    		// }
    		// else{
    			// ans1+=(i.size()/2);
    		// }
    	// }
    	// else{
// 
    		// if(i.size()%2!=0){
    			// // toup = 0;
    			// po =0 ;
    		// }
    		// else{
    			// ans2+=(i.size()/2);
    		// }
    	// }
    // }
    // // cout<<ne<<" "<<po<<endl;
    // if(ne == 0 and po == 0){
    	// cout<<-1<<endl;
    // }
    // else if(ne == 0 and po == 1){
    	// cout<<ans2<<endl;
    // }
    // else if(ne == 1 and po == 0){
    	// cout<<ans1<<endl;
    // }
    // else{
    	// cout<<min(ans1,ans2)<<endl;
    // }



}


signed main(){
    ios::sync_with_stdio(0);//DO NOT USE IN INTERACTIVE
    cin.tie(0), cout.tie(0);
    cout << fixed<<setprecision(9);

    int t = 1;
    // cin>>t;
    for(int i = 1;i<=t;i++){
        solve(i);
    }

}

• Subtask 1: 0 / 3
• Subtask 2: 0 / 3
• Subtask 3: 0 / 3
• Subtask 4: 0 / 4
• Subtask 5: 0 / 4
• Subtask 6: 0 / 3
• Subtask 7: 0 / 2
• Subtask 8: 0 / 3