oj.uz

Submission #330824

# Submission time Handle Problem Language Result Execution time Memory
330824 2020-11-26T16:29:28 Z 12tqian Lamps (JOI19_lamps) C++17
4 / 100
 117 ms 71000 KB 
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <iostream>
#include <iomanip>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <string>
#include <unordered_map>
#include <vector>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>

using namespace std;
using namespace __gnu_pbds;
template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef pair<db, db> pd;

typedef vector<int> vi;
typedef vector<bool> vb;
typedef vector<ll> vl;
typedef vector<db> vd;
typedef vector<str> vs;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<pd> vpd;

#define mp make_pair
#define f first
#define s second
#define sz(x) (int) (x).size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define sor(x) sort(all(x))
#define rsz resize
#define resz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound

#define f1r(i, a, b) for(int i = (a); i < (b); ++i)
#define f0r(i, a) f1r(i, 0, a)
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i,0,a)
#define ROF(i, a, b) for (int i = (b) - 1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define trav(a, x) for (auto& a : x)

mt19937 rng((uint32_t) chrono::steady_clock::now().time_since_epoch().count());

template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

#ifdef LOCAL
#define dbg(...) debug(#__VA_ARGS__, __VA_ARGS__);
#else
#define dbg(...) 17;
#endif

template<typename T, typename S> ostream& operator << (ostream &os, const pair<T, S> &p) { return os << "(" << p.first << ", " << p.second << ")"; }
template<typename C, typename T = decay<decltype(*begin(declval<C>()))>, typename enable_if<!is_same<C, string>::value>::type* = nullptr>
ostream& operator << (ostream &os, const C &c) { bool f = true; os << "{"; for (const auto &x : c) { if (!f) os << ", "; f = false; os << x; } return os << "}"; }
template<typename T> void debug(string s, T x) { cerr << s << " = " << x << "\n"; }
template<typename T, typename... Args> void debug(string s, T x, Args... args) { cerr << s.substr(0, s.find(',')) << " = " << x << " | "; debug(s.substr(s.find(',') + 2), args...); }

constexpr int pct(int x) { return __builtin_popcount(x); }
constexpr int bits(int x) { return 31 - __builtin_clz(x); } // floor(log2(x))

namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1, T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T, SZ>& a);
    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class T, class... Ts> void re(T& t, Ts&... ts) {
        re(t); re(ts...); }
    template<class T> void re(complex<T>& x) { T a, b; re(a, b); x = cd(a, b); }
    template<class T1, class T2> void re(pair<T1, T2>& p) { re(p.f, p.s); }
    template<class T> void re(vector<T>& a) { F0R(i, sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T, SZ>& a) { F0R(i, SZ) re(a[i]); }
}

using namespace input;

namespace output {
    void pr(int x) { cout << x; }
    void pr(long x) { cout << x; }
    void pr(ll x) { cout << x; }
    void pr(unsigned x) { cout << x; }
    void pr(unsigned long x) { cout << x; }
    void pr(unsigned long long x) { cout << x; }
    void pr(float x) { cout << x; }
    void pr(double x) { cout << x; }
    void pr(ld x) { cout << x; }
    void pr(char x) { cout << x; }
    void pr(const char* x) { cout << x; }
    void pr(const string& x) { cout << x; }
    void pr(bool x) { pr(x ? "true" : "false"); }
    template<class T> void pr(const complex<T>& x) { cout << x; }
    template<class T1, class T2> void pr(const pair<T1, T2>& x);
    template<class T> void pr(const T& x);
    template<class T, class... Ts> void pr(const T& t, const Ts&... ts) {
        pr(t); pr(ts...); }
    template<class T1, class T2> void pr(const pair<T1,T2>& x) {
        pr("{", x.f, ", ", x.s, "}"); }
    template<class T> void pr(const T& x) {
        pr("{"); // const iterator needed for vector<bool>
        bool fst = 1; for (const auto& a: x) pr(!fst ? ", " : "", a), fst = 0;
        pr("}"); }
    void ps() { pr("\n"); } // print w/ spaces
    template<class T, class... Ts> void ps(const T& t, const Ts&... ts) {
        pr(t); if (sizeof...(ts)) pr(" "); ps(ts...); }
    void pc() { pr("]\n"); } // debug w/ commas
    template<class T, class... Ts> void pc(const T& t, const Ts&... ts) {
        pr(t); if (sizeof...(ts)) pr(", "); pc(ts...); }
}

using namespace output;

namespace io {
    void setIn(string s) { freopen(s.c_str(), "r", stdin); }
    void setOut(string s) { freopen(s.c_str(), "w", stdout); }
    void setIO(string s = "") {
        cin.sync_with_stdio(0); cin.tie(0);
        if (sz(s)) { setIn(s + ".in"), setOut(s + ".out"); }
    }
}

using namespace io;

const int MOD = 1e9 + 7; // 998244353;
const ld PI = acos((ld) -1);

typedef decay<decltype(MOD)>::type T;
struct mi {
    T val;
    explicit operator T() const { return val; }
    mi() { val = 0; }
    mi(const ll& v) {
        val = (-MOD <= v && v <= MOD) ? v : v % MOD;
        if (val < 0) val += MOD; }
    friend ostream& operator << (ostream& os, const mi& a) { return os << a.val; }
    friend void pr(const mi& a) { pr(a.val); }
    friend void re(mi& a) { ll x; re(x); a = mi(x); }
    friend bool operator == (const mi& a, const mi& b) { return a.val == b.val; }
    friend bool operator != (const mi& a, const mi& b) { return !(a == b); }
    friend bool operator < (const mi& a, const mi& b) { return a.val < b.val; }
    friend bool operator > (const mi& a, const mi& b) { return a.val > b.val; }
    friend bool operator <= (const mi& a, const mi& b) { return a.val <= b.val; }
    friend bool operator >= (const mi& a, const mi& b) { return a.val >= b.val; }
    mi operator - () const { return mi(-val); }
    mi& operator += (const mi& m) {
        if ((val += m.val) >= MOD) val -= MOD;
        return *this; }
    mi& operator -= (const mi& m) {
        if ((val -= m.val) < 0) val += MOD;
        return *this; }
    mi& operator *= (const mi& m) { val = (ll) val * m.val % MOD;
        return *this; }
    friend mi pow(mi a, ll p) {
        mi ans = 1; assert(p >= 0);
        for (; p; p /= 2, a *= a) if (p & 1) ans *= a;
        return ans; }
    friend mi inv(const mi& a) { assert(a != 0); return pow(a, MOD - 2); }
    mi& operator /= (const mi& m) { return (*this) *= inv(m); }
    friend mi operator + (mi a, const mi& b) { return a += b; }
    friend mi operator - (mi a, const mi& b) { return a -= b; }
    friend mi operator * (mi a, const mi& b) { return a *= b; }
    friend mi operator / (mi a, const mi& b) { return a /= b; }
};

typedef pair<mi, mi> pmi;
typedef vector<mi> vmi;
typedef vector<pmi> vpmi;

int main() {
    setIO("");
    int n; re(n);
    string  astr, bstr; re(astr, bstr);
    vi a(n), b(n), c(n); // a is what you have, b is target, c is xor
    f0r(i, n) a[i] = astr[i] - '0', b[i] = bstr[i] - '0', c[i] = a[i] ^ b[i];
    const int INF = 1e9;
    a.insert(a.begin(), -1);
    b.insert(b.begin(), -1);
    c.insert(c.begin(), -1); 
    vector<vector<int>> dp(n+1, vector<int>(6, INF));
    if (b[1] == 0) dp[1][0] = 1;
    if (b[1] == 1) dp[1][3] = 1;
    if (a[1] != b[1]) dp[1][4] = 1;
    if (a[1] == b[1]) dp[1][5] = 0;
    f1r(i, 2, n+1) { 
        // continue off old thing
        if (dp[i-1][0] != INF) {
            if (b[i] == 0) ckmin(dp[i][0], dp[i-1][0]);
            if (b[i] == 1) ckmin(dp[i][1], dp[i-1][0]+1);
        }
        if (dp[i-1][1] != INF) {
            if (b[i] == 1) ckmin(dp[i][1], dp[i-1][1]);
            if (b[i] == 0) ckmin(dp[i][0], dp[i-1][1]);
            if (a[i] != b[i]) ckmin(dp[i][4], dp[i-1][1]);

        } 
        if (dp[i-1][2] != INF) {
            if (b[i] == 0) ckmin(dp[i][2], dp[i-1][2]);
            if (b[i] == 1) ckmin(dp[i][3], dp[i-1][2]);
            if (a[i] != b[i]) ckmin(dp[i][4], dp[i-1][2]+1);
        }
        if (dp[i-1][3] != INF) {
            if (b[i] == 1) ckmin(dp[i][3], dp[i-1][3]);
            if (b[i] == 0) ckmin(dp[i][2], dp[i-1][3]+1);
        }
        if (dp[i-1][4] != INF) {
            if (a[i] != b[i]) ckmin(dp[i][4], dp[i-1][4]);
            if (b[i] == 1) ckmin(dp[i][1], dp[i-1][4]+1);
            if (b[i] == 0) ckmin(dp[i][2], dp[i-1][4]+1);
        }
        // start a new thing
        int mn = INF;
        f0r(j, 6) ckmin(mn, dp[i-1][j]);
        if (b[i] == 0) ckmin(dp[i][0], mn+1);
        if (b[i] == 1) ckmin(dp[i][3], mn+1);
        if (a[i] != b[i]) ckmin(dp[i][4], mn+1);
        if (a[i] == b[i]) ckmin(dp[i][5], mn);
    }
    int ans = INF;
    f0r(j, 6) ckmin(ans, dp[n][j]);
    ps(ans);
    // three things you can do 
    // start a new chain of things to go onwards
    // note that you should always extend something as far right as you can go
    // if you start a new chain, you add 1 to your counter and you jump to the end of your current chain if you're in the middle of one or the end of the next chain if you finished one
    // you store the chain base, so you know when you're just contributing something else
    // if you've just finished an opposite side of a chain, you can go to the opposite number as far as you can go
    // the other case is if you decide to not start a chain, and instead just go opposite
    // then you just go opposite as far as you can go
    // but the other possibility is if you go opposite but in the beginning of a chain
    // in this case you just go opposite for some part, then you decide what your chain base will be, and you store as a chain that can't be carried on as opposite
    // is there a better implementation of this? this seems pretty annoying
    // if it's the same just do nothing to it
    return 0;
}

Compilation message

lamp.cpp: In function 'void io::setIn(std::string)':
lamp.cpp:152:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  152 |     void setIn(string s) { freopen(s.c_str(), "r", stdin); }
      |                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
lamp.cpp: In function 'void io::setOut(std::string)':
lamp.cpp:153:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
  153 |     void setOut(string s) { freopen(s.c_str(), "w", stdout); }
      |                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 0 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 0 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 1 ms 364 KB Output is correct
24 Correct 1 ms 364 KB Output is correct
25 Correct 1 ms 364 KB Output is correct
26 Incorrect 1 ms 364 KB Output isn't correct
27 Halted 0 ms 0 KB -

Subtask #2
0 / 41.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 0 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 0 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 1 ms 364 KB Output is correct
24 Correct 1 ms 364 KB Output is correct
25 Correct 1 ms 364 KB Output is correct
26 Incorrect 1 ms 364 KB Output isn't correct
27 Halted 0 ms 0 KB -

Subtask #3
4.0 / 4.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 0 ms 364 KB Output is correct
3 Correct 1 ms 368 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 103 ms 71000 KB Output is correct
8 Correct 107 ms 70752 KB Output is correct
9 Correct 105 ms 70868 KB Output is correct
10 Correct 106 ms 70752 KB Output is correct
11 Correct 104 ms 70752 KB Output is correct
12 Correct 117 ms 70752 KB Output is correct
13 Correct 103 ms 70752 KB Output is correct
14 Correct 106 ms 70880 KB Output is correct

Subtask #4
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 364 KB Output is correct
2 Correct 1 ms 364 KB Output is correct
3 Correct 0 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 0 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 1 ms 364 KB Output is correct
22 Correct 1 ms 364 KB Output is correct
23 Correct 1 ms 364 KB Output is correct
24 Correct 1 ms 364 KB Output is correct
25 Correct 1 ms 364 KB Output is correct
26 Incorrect 1 ms 364 KB Output isn't correct
27 Halted 0 ms 0 KB -