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Submission #251030

# Submission time Handle Problem Language Result Execution time Memory
251030 2020-07-20T00:28:05 Z rqi Kangaroo (CEOI16_kangaroo) C++14
36 / 100
 2000 ms 37704 KB 
#include <bits/stdc++.h>
using namespace std;
 
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<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 rsz 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 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)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
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; } 
int pct(int x) { return __builtin_popcount(x); } 
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 
int fstTrue(function<bool(int)> f, int lo, int hi) {
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        int mid = (lo+hi)/2; 
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) { 
    str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string s = "") {
    unsyncIO();
    // cin.exceptions(cin.failbit); 
    // throws exception when do smth illegal
    // ex. try to read letter into int
    if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}

/**
 * Description: modular arithmetic operations 
 * Source: 
    * KACTL
    * https://codeforces.com/blog/entry/63903
    * https://codeforces.com/contest/1261/submission/65632855 (tourist)
    * https://codeforces.com/contest/1264/submission/66344993 (ksun)
 * Verification: 
    * https://open.kattis.com/problems/modulararithmetic
 */

struct mi {
    typedef decay<decltype(MOD)>::type T; 
     /// don't silently convert to T
    T v; explicit operator T() const { return v; }
    mi() { v = 0; }
    mi(ll _v) { 
        v = (-MOD < _v && _v < MOD) ? _v : _v % MOD;
        if (v < 0) v += MOD;
    }
    friend bool operator==(const mi& a, const mi& b) { 
        return a.v == b.v; }
    friend bool operator!=(const mi& a, const mi& b) { 
        return !(a == b); }
    friend bool operator<(const mi& a, const mi& b) { 
        return a.v < b.v; }
    friend void re(mi& a) { ll x; re(x); a = mi(x); }
    friend str ts(mi a) { return ts(a.v); }
   
    mi& operator+=(const mi& m) { 
        if ((v += m.v) >= MOD) v -= MOD; 
        return *this; }
    mi& operator-=(const mi& m) { 
        if ((v -= m.v) < 0) v += MOD; 
        return *this; }
    mi& operator*=(const mi& m) { 
        v = (ll)v*m.v%MOD; return *this; }
    mi& operator/=(const mi& m) { return (*this) *= inv(m); }
    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.v != 0); 
        return pow(a,MOD-2); }
        
    mi operator-() const { return mi(-v); }
    mi& operator++() { return *this += 1; }
    mi& operator--() { return *this -= 1; }
    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 vector<mi> vmi;
typedef pair<mi,mi> pmi;
typedef vector<pmi> vpmi;

vector<vmi> scmb; // small combinations
void genComb(int SZ) {
    scmb.assign(SZ,vmi(SZ)); scmb[0][0] = 1;
    FOR(i,1,SZ) F0R(j,i+1) 
        scmb[i][j] = scmb[i-1][j]+(j?scmb[i-1][j-1]:0);
}


typedef pair<vi, pair<bool, bool>> T; //is start > end? is kang facing right?
map<T, mi> m;
map<T, bool> done;

int main() {
    setIO();
    int N, cs, cf;
    cin >> N >> cs >> cf;

    T start1, start2;
    if(cs < cf){
        start1 = mp(vi{cs-1, cf-cs-1, N-cf}, mp(0, 0));
        start2 = mp(vi{cs-1, cf-cs-1, N-cf}, mp(0, 1));
    }
    else{
        start1 = mp(vi{cf-1, cs-cf-1, N-cs}, mp(1, 0));
        start2 = mp(vi{cf-1, cs-cf-1, N-cs}, mp(1, 1));
    }

    m[start1] = mi(1);
    m[start2] = mi(1);
    queue<T> q;
    q.push(start1);
    q.push(start2);
    while(sz(q)){
        T a = q.front();
        q.pop();
        if(done[a]) continue;
        //dbg(a, m[a]);
        done[a] = 1;
        if(a.s.f == 0 && a.s.s == 0){
            for(int i = a.f[0]-1; i >= 0; i--){
                vi newv;
                T newa;
                newv = a.f;
                newv[0] = i;
                newv[1] = a.f[0]+a.f[1]-i-1;
                newa = mp(newv, mp(0, 1));
                if(newa.f[0] < 0 || newa.f[1] < 0 || newa.f[2] < 0) continue;
                m[newa]+=m[a];
                //dbg(newa);
                q.push(newa);
            }
        }
        else if(a.s.f == 0 && a.s.s == 1){
            for(int i = a.f[0]; i <= a.f[0]+a.f[1]-1; i++){
                vi newv;
                T newa;
                newv = a.f;
                newv[0] = i;
                newv[1] = a.f[0]+a.f[1]-i-1;
                newa = mp(newv, mp(0, 0));
                if(newa.f[0] < 0 || newa.f[1] < 0 || newa.f[2] < 0) continue;
                m[newa]+=m[a];
                //dbg(newa);
                q.push(newa);
            }
            for(int i = a.f[2]-1; i >= 0; i--){
                vi newv;
                T newa;
                newv = a.f;
                newv[2] = i;
                newv[1] = a.f[2]-i-1;
                newv[0] = a.f[0]+a.f[1];
                newa = mp(newv, mp(1, 0));
                if(newa.f[0] < 0 || newa.f[1] < 0 || newa.f[2] < 0) continue;
                m[newa]+=m[a];
                //dbg(newa);
                q.push(newa);
            }
        }
        else if(a.s.f == 1 && a.s.s == 0){
            for(int i = a.f[2]; i <= a.f[2]+a.f[1]-1; i++){
                vi newv;
                T newa;
                newv = a.f;
                newv[2] = i;
                newv[1] = a.f[2]+a.f[1]-i-1;
                newa = mp(newv, mp(1, 1));
                if(newa.f[0] < 0 || newa.f[1] < 0 || newa.f[2] < 0) continue;
                m[newa]+=m[a];
                //dbg(newa);
                q.push(newa);
            }
            for(int i = a.f[0]-1; i >= 0; i--){
                vi newv;
                T newa;
                newv = a.f;
                newv[0] = i;
                newv[1] = a.f[0]-i-1;
                newv[2] = a.f[2]+a.f[1];
                newa = mp(newv, mp(0, 1));
                if(newa.f[0] < 0 || newa.f[1] < 0 || newa.f[2] < 0) continue;
                m[newa]+=m[a];
                //dbg(newa);
                q.push(newa);
            }
        }
        else if(a.s.f == 1 && a.s.s == 1){
            for(int i = a.f[2]-1; i >= 0; i--){
                vi newv;
                T newa;
                newv = a.f;
                newv[2] = i;
                newv[1] = a.f[2]+a.f[1]-i-1;
                newa = mp(newv, mp(1, 0));
                if(newa.f[0] < 0 || newa.f[1] < 0 || newa.f[2] < 0) continue;
                m[newa]+=m[a];
                //dbg(newa);
                q.push(newa);
            }
        }
        else assert(0 == 1);
    }
    ps(m[mp(vi{0, 0, 0}, mp(0, 1))]+m[mp(vi{0, 0, 0}, mp(1, 0))]);
    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message

kangaroo.cpp: In function 'void setIn(std::__cxx11::string)':
kangaroo.cpp:128:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
kangaroo.cpp: In function 'void setOut(std::__cxx11::string)':
kangaroo.cpp:129:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
6.0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 71 ms 2420 KB Output is correct
5 Correct 5 ms 640 KB Output is correct
6 Correct 111 ms 3448 KB Output is correct
7 Correct 85 ms 2680 KB Output is correct
8 Correct 19 ms 896 KB Output is correct
9 Correct 113 ms 3448 KB Output is correct
10 Correct 56 ms 2040 KB Output is correct
11 Correct 55 ms 2040 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 71 ms 2420 KB Output is correct
5 Correct 5 ms 640 KB Output is correct
6 Correct 111 ms 3448 KB Output is correct
7 Correct 85 ms 2680 KB Output is correct
8 Correct 19 ms 896 KB Output is correct
9 Correct 113 ms 3448 KB Output is correct
10 Correct 56 ms 2040 KB Output is correct
11 Correct 55 ms 2040 KB Output is correct
12 Execution timed out 2088 ms 37704 KB Time limit exceeded
13 Halted 0 ms 0 KB -

Subtask #4
0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 2 ms 384 KB Output is correct
4 Correct 71 ms 2420 KB Output is correct
5 Correct 5 ms 640 KB Output is correct
6 Correct 111 ms 3448 KB Output is correct
7 Correct 85 ms 2680 KB Output is correct
8 Correct 19 ms 896 KB Output is correct
9 Correct 113 ms 3448 KB Output is correct
10 Correct 56 ms 2040 KB Output is correct
11 Correct 55 ms 2040 KB Output is correct
12 Execution timed out 2088 ms 37704 KB Time limit exceeded
13 Halted 0 ms 0 KB -