Submission #943846

#	Time	Username	Problem	Language	Result	Execution time	Memory
943846		yeediot	Lamps (JOI19_lamps)	C++17	4 / 100	34 ms	51296 KiB

lamp

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define F first
#define S second
#define all(x) x.begin(),x.end()
#define pii pair<int,int>
#define pb push_back
#define sz(x) (int)(x.size())
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
#define vi vector<int>
#define vp vector<pii>
#define vvi vector<vi>
#define ykh mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count())
#define __lg(x) 63-__builtin_clzll(x)
#define pow2(x) (1LL<<x)
void __print(int x) {cerr << x;}
void __print(float x) {cerr << x;}
void __print(double x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << '\'' << x << '\'';}
void __print(const char *x) {cerr << '\"' << x << '\"';}
void __print(const string &x) {cerr << '\"' << x << '\"';}
void __print(bool x) {cerr << (x ? "true" : "false");}

template<typename T, typename V>
void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
template<typename T>
void __print(const T &x) {int f = 0; cerr << '{'; for (auto &i: x) cerr << (f++ ? "," : ""), __print(i); cerr << "}";}
void _print() {cerr << "]\n";}
template <typename T, typename... V>
void _print(T t, V... v) {__print(t); if (sizeof...(v)) cerr << ", "; _print(v...);}
#ifdef local
void setio(){freopen("/Users/iantsai/Library/Mobile Documents/com~apple~CloudDocs/cpp/Empty.md","r",stdin);}
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
void setio(){}
#define debug(x...)
#endif
void setIO(string s) {
    freopen((s + ".in").c_str(), "r", stdin);
    freopen((s + ".out").c_str(), "w", stdout);
}
struct line{
    int a,b;
    int operator()(const int x)const{
        return a*x+b;
    }
};
bool check(line l1,line l2,line l3){
    return (l3.b-l2.b)*(l1.a-l2.a)<=(l2.b-l1.b)*(l2.a-l3.a);
}
const int mxn=1e6+5;
int dp[mxn][3][2];// [0/1/2]第i位用了on/off [0/1]第i位用了tog
void upd(int i,int l,int r,bool tf=1){
    for(int j=0;j<3;j++){
        for(int k=0;k<2;k++){
            chmin(dp[i][l][r],dp[i-1][j][k]+tf);
        }
    }
}
signed main(){
    setio();
    ios::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n;
    cin>>n;
    string a,b;
    cin>>a>>b;
    a=" "+a;
    b=" "+b;
    memset(dp,0x3f3f3f3f,sizeof(dp));
    dp[0][0][0]=0;
    for(int i=1;i<=n;i++){
        if(a[i]==b[i]){
            upd(i,0,0,0);
        }
        if(a[i]=='0' and b[i]=='0'){
            upd(i,1,0);
            chmin(dp[i][1][0],min(dp[i-1][1][0],dp[i-1][1][1]));
        }
        if(a[i]=='1' and b[i]=='1'){
            upd(i,2,0);
            chmin(dp[i][2][0],min(dp[i-1][2][0],dp[i-1][2][1]));
        }
        if(a[i]=='1' and b[i]=='0'){
            upd(i,1,0);
            chmin(dp[i][1][0],min(dp[i-1][1][0],dp[i-1][1][1]));
            upd(i,0,1);
            chmin(dp[i][0][1],min({dp[i-1][0][1],dp[i-1][1][1],dp[i-1][2][1]}));
        }
        if(a[i]=='0' and b[i]=='1'){
            upd(i,2,0);
            chmin(dp[i][2][0],min(dp[i-1][2][0],dp[i-1][2][1]));
            upd(i,0,1);
            chmin(dp[i][0][1],min({dp[i-1][0][1],dp[i-1][1][1],dp[i-1][2][1]}));
        }
        debug(dp[i][0][0],dp[i][0][1],dp[i][1][0],dp[i][1][1],dp[i][2][0],dp[i][2][1]);
    }
    cout<<min({dp[n][0][0],dp[n][0][1],dp[n][1][0],dp[n][1][1],dp[n][2][0],dp[n][2][1]})<<'\n';
}
 /*
 input:
 
 */















 

Compilation message (stderr)

lamp.cpp: In function 'void setIO(std::string)':
lamp.cpp:42:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   42 |     freopen((s + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
lamp.cpp:43:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     freopen((s + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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