Submission #427949

#	Time	Username	Problem	Language	Result	Execution time	Memory
427949		juggernaut	Lamps (JOI19_lamps)	C++17	0 / 100	55 ms	9160 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;
int dp[200005];
int b[200005];
int c[200005];
string A,B;
int main(){
    cin>>n>>A>>B;
    A=" "+A;
    B=" "+B;
    for(int i=1;i<=n;i++){
        b[i]=b[i-1]+(B[i]=='0');
        c[i]=c[i-1]+(B[i]!=A[i]);
    }
    for(int i=1;i<=n;i++){
        dp[i]=i;
        for(int j=1;j<=i;j++){
            if(b[i]-b[j-1]==0||b[i]-b[j-1]==i-j+1)umin(dp[i],dp[j-1]+1);
            if(c[i]-c[j-1]==0)umin(dp[i],dp[j-1]);
            if(c[i]-c[j-1]==i-j+1)umin(dp[i],dp[j-1]+1);
        }
    }
    cout<<dp[n];
}

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