Submission #427979

#	Time	Username	Problem	Language	Result	Execution time	Memory
427979		juggernaut	Lamps (JOI19_lamps)	C++17	6 / 100	479 ms	21872 KiB

lamp

#include<bits/stdc++.h>
#define fr first
#define sc second
using namespace std;
void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
typedef long long ll;
#define USING_ORDERED_SET 0
#if USING_ORDERED_SET
#include<bits/extc++.h>
using namespace __gnu_pbds;
template<class T>using ordered_set=tree<T,null_type,less<T>,rb_tree_tag,tree_order_statistics_node_update>;
#endif
template<class T>void umax(T &a,T b){if(a<b)a=b;}
template<class T>void umin(T &a,T b){if(b<a)a=b;}
#ifdef IOI2021SG
    #define printl(args...)printf(args)
#else
    #define printl(args...)((void)0)
#endif
int n;
string a,b;
int dp[262144];
int go(int mask){
    if(~dp[mask])return dp[mask];
    dp[mask]=1e9;
    for(int i=0;i<n;i++){
        int A=mask;
        int B=mask;
        int C=mask;
        for(int j=i;j<n;j++){
            if(mask>>j&1)A^=(1<<j);
            else B^=(1<<j);
            C^=(1<<j);
            umin(dp[mask],go(A)+1);
            umin(dp[mask],go(B)+1);
            umin(dp[mask],go(C)+1);
        }
    }
    return dp[mask];
}
int main(){
    memset(dp,-1,sizeof dp);
    cin>>n>>b>>a;
    int cnt=0;
    int dest=0;
    for(int i=0;i<n;i++)cnt|=((a[i]=='1')<<i);
    for(int i=0;i<n;i++)dest|=((b[i]=='1')<<i);
    dp[cnt]=0;
    cout<<go(dest);
}

Compilation message (stderr)

lamp.cpp: In function 'void usaco(std::string)':
lamp.cpp:5:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lamp.cpp:5:66: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | void usaco(string s){freopen((s+".in").c_str(),"r",stdin);freopen((s+".out").c_str(),"w",stdout);}
      |                                                           ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 0 / 41
• Subtask 3: 0 / 4
• Subtask 4: 0 / 49