oj.uz

Submission #299845

# Submission time Handle Problem Language Result Execution time Memory
299845 2020-09-15T19:56:44 Z limabeans Xylophone (JOI18_xylophone) C++17
100 / 100
 72 ms 532 KB 
#include "xylophone.h"
#include <bits/stdc++.h>
using namespace std;

template<typename T>
void out(T x) { cout << x << endl; exit(0); }
#define watch(x) cout << (#x) << " is " << (x) << endl

void solve(int N);
int query(int s, int t);
void answer(int i, int a);


using ll = long long;

const ll mod = 1e9+7;
const int maxn = 1e6 + 5;

int A[maxn];
int n;


bool used[maxn];
int A1[maxn];
int A2[maxn];

void Set(int i, int a) {
    answer(i,a);
    used[a]=true;
    A[i]=a;
}


void ask1(int i) {
    if (A1[i]) return;
    A1[i] = query(i,i+1);
}

void ask2(int i) {
    assert(i+2<=n);
    if (A2[i]) return;
    A2[i] = query(i,i+2);
}

bool isUsed(int x) {
    if (x<1 || x>n) return true;
    return used[x];
}

void solve(int _n) {
    n=_n;
    int in = -1;
    // find where A[in]=n is
    {
	int lo = 1;
	int hi = n;
	while (hi-lo>1) {
	    int mid = (lo+hi)/2;
	    if (query(1,mid)==n-1) {
		hi = mid;
	    } else {
		lo = mid;
	    }
	}
	in = hi;
    }


    // A[i+1] and A[i+2] are fixed, solve for A[i]
    auto bruteL = [&](int i) {
	assert(i+2<=n);
	assert(A[i+1]); assert(A[i+2]);
	ask1(i);
	ask1(i+1);
	ask2(i);
	vector<int> op;
	op.push_back(A[i+1]-A1[i]);
	op.push_back(A[i+1]+A1[i]);
	for (int x: op) {
	    if (x<1 || x>n) continue;
	    A[i]=x;
	    bool ok = true;
	    int gap=max(abs(A[i]-A[i+1]),abs(A[i+1]-A[i+2]));
	    if (gap > A2[i]) {
		ok = false;
	    }
	    if (A1[i] < A2[i] && A1[i+1]==A2[i]) {
		// we have to be in the middle
		// 2 3 1 or 2 1 3
		int lo = min(A[i+1],A[i+2]);
		int hi = max(A[i+1],A[i+2]);
		if (!(lo<A[i] && A[i]<hi)) {
		    ok = false;
		}
	    } else if (A1[i]==A2[i] && A1[i+1]<A2[i]) {
		// 3 1 2 or 1 3 2
		if (A[i+1]<A[i+2]) {
		    if (!(A[i]>max(A[i+1],A[i+2]))) {
			ok = false;
		    }
		} else if (A[i+1]>A[i+2]) {
		    if (!(A[i]<min(A[i+1],A[i+2]))) {
			ok = false;
		    }
		} else {
		    assert(false);
		}
	    } else if (A1[i]<A2[i] && A1[i+1]<A2[i]) {
		// 1 2 3 or 3 2 1
		if (A[i+1]<A[i+2]) {
		    if (!(A[i]<A[i+1])) {
			ok = false;
		    }
		}
		if (A[i+1]>A[i+2]) {
		    if (!(A[i]>A[i+1])) {
			ok = false;
		    }
		}
	    } else {
		assert(false);
	    }

	    if (ok) {
		Set(i,x);
		break;
	    }
	}
    };

    // A[i] and A[i+1] are fixed, solve for A[i+2]
    auto bruteR = [&](int i) {
	ask1(i);
	ask2(i);
	ask1(i+1);
	assert(A[i]);
	assert(A[i+1]);
	vector<int> op;
	op.push_back(A[i+1]-A1[i+1]);
	op.push_back(A[i+1]+A1[i+1]);

	for (int x: op) {
	    if (x<1 || x>n) continue;
	    if (isUsed(x)) continue;
	    A[i+2] = x;
	    bool ok = true;
	    if (A1[i]<A2[i] && A1[i+1]<A2[i]) {
		// 1 2 3 or 3 2 1
		if (A[i]<A[i+1]) {
		    if (!(A[i+1]<A[i+2])) {
			ok = false;
		    }
		} else if (A[i]>A[i+1]) {
		    if (!(A[i+1]>A[i+2])) {
			ok = false;
		    }
		} else {
		    assert(false);
		}
	    } else if (A1[i]==A2[i] && A1[i+1]<A2[i]) {
		// 1 3 2 or 3 1 2
		int lo = min(A[i],A[i+1]);
		int hi = max(A[i],A[i+1]);
		if (!(lo<=A[i+2] && A[i+2]<=hi)) {
		    ok = false;
		}
	    } else if (A1[i+1]==A2[i] && A1[i]<A2[i]) {
		// 2 3 1
		// 2 1 3
		int lo = min(A[i+1],A[i+2]);
		int hi = max(A[i+1],A[i+2]);
		if (!(lo<=A[i] && A[i]<=hi)) {
		    ok = false;
		}
		if (A[i]>A[i+1]) {
		    if (!(A[i+2]>A[i])) {
			ok = false;
		    }
		} else if (A[i]<A[i+1]) {
		    if (!(A[i+2]<A[i])) {
			ok = false;
		    }
		} else {
		    assert(false);
		}
	    } else {
		assert(false);
	    }

	    if (ok) {
		Set(i+2,x);
		break;
	    }
	}

	// 1 2 3
	// 1 3 2
	// 2 1 3
	// 2 3 1
	// 3 1 2
	// 3 2 1
    };

    Set(in,n);
    // go left
    for (int i=in-1; i>=1; i--) {
	ask1(i);
	int dif=A1[i];
	if (isUsed(A[i+1]-dif)) {
	    Set(i, A[i+1]+dif);
	} else if (isUsed(A[i+1]+dif)) {
	    Set(i, A[i+1]-dif);
	} else {
	    assert(i+2<=n);
	    bruteL(i);
	    assert(A[i]);
	}
    }

    for (int i=in; i<n-1; i++) {
    	ask1(i);
    	int dif=A1[i];
    	if (isUsed(A[i]-dif)) {
    	    Set(i+1, A[i]+dif);
    	} else if (isUsed(A[i]+dif)) {
    	    Set(i+1, A[i]-dif);
    	} else {
    	    assert(i-1>=1);
    	    bruteR(i-1);
	    assert(A[i+1]);
    	}
    }

    for (int i=1; i<=n; i++) {
	if (!isUsed(i)) {
	    Set(n,i);
	    break;
	}
    }
}

///////////////////////////////////////////////////////////////////////////
/*

int nn;
vector<int> v = {-1,4,6,5,1,7,3,2,9,8};
int query(int s, int t) {
    assert(s<=t);
    int mx=0;
    for (int i=s; i<=t; i++) {
	for (int j=i; j<=t; j++) {
	    mx=max(mx,abs(v[i]-v[j]));
	}
    }
    return mx;
}


void answer(int i, int a) {
    A[i]=a;
}

void print() {
    cout<<"v: ";
    for (int i=1; i<=nn; i++) {
	cout<<v[i]<<" ";
    }
    cout<<endl;
    cout<<"A: ";
    for (int i=1; i<=nn; i++) {
	cout<<A[i]<<" ";
    }
    cout<<endl;
}

vector<int> rand_perm(int n, int index=1) {
    assert(n>=1);
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    vector<int> a(n);
    iota(a.begin(), a.end(), index);
    shuffle(a.begin(), a.end(), rng);
    return a;
}

vector<int> genV(int n) {
    vector<int> v = rand_perm(n, 1);
    v.insert(v.begin(), -1);
    int i1= -1; int in = -1;
    for (int i=1; i<=n; i++) {
	if (v[i]==1) i1=i;
	if (v[i]==n) in=i;
    }
    if (i1>in) {
	swap(v[i1],v[in]);
    }

    //v = {-1, 1, 10, 2, 9, 3, 5, 8, 7, 6, 4};
    //v = {-1, 2, 1, 5, 7, 8, 3, 10, 9, 6, 4};
    //v = {-1, 6, 2, 5, 8, 7, 9, 1, 10, 3, 4 };
    // v = {-1,6, 1, 4, 10, 8, 9, 7, 3, 2, 5 };
    // v = {-1,2, 9, 1, 3, 10, 5, 6, 4, 7, 8};
    return v;
}

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);  cout.tie(0);

    v = genV(100);
    nn = (int)v.size() - 1;
    //print();
    solve(nn);
    print();
    for (int i=1; i<=nn; i++) {
	assert(A[i]==v[i]);
    }
    
    
    return 0;
}
*/

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 288 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 512 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 1 ms 388 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 2 ms 384 KB Output is correct
13 Correct 2 ms 384 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct

Subtask #2
36.0 / 36.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 288 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 512 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 1 ms 388 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 2 ms 384 KB Output is correct
13 Correct 2 ms 384 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 4 ms 384 KB Output is correct
17 Correct 6 ms 512 KB Output is correct
18 Correct 9 ms 384 KB Output is correct
19 Correct 7 ms 528 KB Output is correct
20 Correct 13 ms 384 KB Output is correct
21 Correct 13 ms 384 KB Output is correct
22 Correct 14 ms 384 KB Output is correct
23 Correct 12 ms 384 KB Output is correct
24 Correct 10 ms 384 KB Output is correct
25 Correct 10 ms 384 KB Output is correct
26 Correct 7 ms 532 KB Output is correct
27 Correct 13 ms 384 KB Output is correct
28 Correct 13 ms 384 KB Output is correct
29 Correct 13 ms 384 KB Output is correct
30 Correct 13 ms 384 KB Output is correct

Subtask #3
53.0 / 53.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 288 KB Output is correct
2 Correct 1 ms 384 KB Output is correct
3 Correct 1 ms 384 KB Output is correct
4 Correct 2 ms 384 KB Output is correct
5 Correct 2 ms 384 KB Output is correct
6 Correct 2 ms 512 KB Output is correct
7 Correct 2 ms 384 KB Output is correct
8 Correct 1 ms 388 KB Output is correct
9 Correct 2 ms 384 KB Output is correct
10 Correct 1 ms 384 KB Output is correct
11 Correct 1 ms 384 KB Output is correct
12 Correct 2 ms 384 KB Output is correct
13 Correct 2 ms 384 KB Output is correct
14 Correct 1 ms 384 KB Output is correct
15 Correct 1 ms 384 KB Output is correct
16 Correct 4 ms 384 KB Output is correct
17 Correct 6 ms 512 KB Output is correct
18 Correct 9 ms 384 KB Output is correct
19 Correct 7 ms 528 KB Output is correct
20 Correct 13 ms 384 KB Output is correct
21 Correct 13 ms 384 KB Output is correct
22 Correct 14 ms 384 KB Output is correct
23 Correct 12 ms 384 KB Output is correct
24 Correct 10 ms 384 KB Output is correct
25 Correct 10 ms 384 KB Output is correct
26 Correct 7 ms 532 KB Output is correct
27 Correct 13 ms 384 KB Output is correct
28 Correct 13 ms 384 KB Output is correct
29 Correct 13 ms 384 KB Output is correct
30 Correct 13 ms 384 KB Output is correct
31 Correct 30 ms 384 KB Output is correct
32 Correct 36 ms 384 KB Output is correct
33 Correct 51 ms 384 KB Output is correct
34 Correct 63 ms 384 KB Output is correct
35 Correct 57 ms 384 KB Output is correct
36 Correct 47 ms 504 KB Output is correct
37 Correct 49 ms 384 KB Output is correct
38 Correct 41 ms 504 KB Output is correct
39 Correct 64 ms 460 KB Output is correct
40 Correct 53 ms 504 KB Output is correct
41 Correct 63 ms 384 KB Output is correct
42 Correct 46 ms 504 KB Output is correct
43 Correct 48 ms 384 KB Output is correct
44 Correct 52 ms 384 KB Output is correct
45 Correct 72 ms 384 KB Output is correct
46 Correct 47 ms 504 KB Output is correct
47 Correct 67 ms 384 KB Output is correct
48 Correct 60 ms 504 KB Output is correct
49 Correct 66 ms 532 KB Output is correct
50 Correct 63 ms 384 KB Output is correct
51 Correct 55 ms 384 KB Output is correct
52 Correct 62 ms 384 KB Output is correct
53 Correct 56 ms 504 KB Output is correct
54 Correct 58 ms 384 KB Output is correct
55 Correct 54 ms 504 KB Output is correct
56 Correct 57 ms 504 KB Output is correct
57 Correct 61 ms 508 KB Output is correct
58 Correct 58 ms 504 KB Output is correct
59 Correct 58 ms 532 KB Output is correct
60 Correct 44 ms 504 KB Output is correct