Submission #681316

# Submission time Handle Problem Language Result Execution time Memory
681316 2023-01-12T18:20:05 Z USER XOR Sum (info1cup17_xorsum) C++14
56 / 100
1600 ms 33484 KB
#include <bits/stdc++.h> 
using namespace std;
 
class Input {
private:
    char* t;
    int sp;
    const int sz = 10000;
 
    char read()
    {
        if (sp == sz)
        {
            fread(t, 1, sz, stdin);
            sp = 0;
            return t[sp++];
        }
        else
            return t[sp++];
    }
public:
    Input()
    {
        sp = sz;
        t = new char[sz]();
    }
 
    Input& operator >> (int& n)
    {
        char c = read();
 
        while (c == ' ' || c == '\n')
            c = read();
 
        n = 0;
 
        int sng = 1;
 
        if (c == '-')
            sng = -1, c = read();
 
        while (c != '\0' && isdigit(c))
            n = n * 10 + (c - '0'), c = read();
 
        n *= sng;
 
        return *this;
    }
 
    Input& operator >> (char& s)
    {
        char c = read();
 
        while (c != '\0' && c == '\n')
            c = read();
 
        s = c;
 
        return *this;
    }
 
    Input& operator >> (long long& n)
    {
        char c = read();
 
        while (c == ' ' || c == '\n')
            c = read();
 
        n = 0;
 
        int sng = 1;
 
        if (c == '-')
            sng = -1, c = read();
 
        while (c != '\0' && isdigit(c))
            n = n * 10 + (c - '0'), c = read();
 
        n *= sng;
 
        return *this;
    }
 
    void getline(string& s)
    {
        char c = read();
        s = "";
 
        while (c != '\0' && c != '\n')
            s += c, c = read();
    }
 
    Input& operator >> (string& s)
    {
        char c;
        c = read();
        s = "";
 
        while (c == '\n' || c == ' ')
            c = read();
 
        while (c != '\n' && c != '\0' && c != ' ')
            s += c, c = read();
 
        return *this;
    }
 
    Input& operator >> (char* s)
    {
        char c;
        c = read();
        int i = 0;
 
        while (c == '\n' || c == ' ')
            c = read();
 
        while (c != '\n' && c != '\0' && c != ' ')
            s[i++] = c, c = read();
 
        return *this;
    }
};
class Output {
private:
    char* t;
    int sp;
    const int sz = 10000;
 
    void write(char c)
    {
        if (sp == sz)
        {
            fwrite(t, 1, sz, stdout);
            sp = 0;
            t[sp++] = c;
        }
        else
            t[sp++] = c;
    }
 
public:
    Output()
    {
        sp = 0;
        t = new char[sz]();
    }
 
    ~Output()
    {
        fwrite(t, 1, sp, stdout);
    }
 
    Output& operator << (int n)
    {
        if (n < 0)
        {
            write('-');
            n *= -1;
        }
        if (n <= 9)
            write(char(n + '0'));
        else
        {
            (*this) << (n / 10);
            write(char(n % 10 + '0'));
        }
 
        return *this;
    }
 
    Output& operator << (char c)
    {
        write(c);
 
        return *this;
    }
 
    Output& operator << (const char* s)
    {
        int i = 0;
 
        while (s[i] != '\0')
            write(s[i++]);
 
        return *this;
    }
 
    Output& operator << (long long n)
    {
        if (n < 0)
        {
            write('-');
            n *= -1;
        }
        if (n < 10)
            write(char(n + '0'));
        else
        {
            (*this) << (n / 10);
            write(char(n % 10 + '0'));
        }
 
        return *this;
    }
 
    Output& operator << (string s)
    {
        for (auto i : s)
            write(i);
 
        return *this;
    }
 
    void precizion(double x, int nr)
    {
        int p = int(floor(x));
 
        *this << p;
 
        if (nr == 0)
            return;
 
        write('.');
 
        for (int i = 1; i <= nr; i++)
        {
            x -= floor(x);
            x *= 10;
 
            write(int(x) + '0');
        }
    }
};
 
Input fin;
Output fout;
 
// (((1 << k) <= nr && nr < (1 << (k + 1))) || (nr >= (1 << k) + (1 << (k + 1))))
 
int v[1000001], X[1000001], n, POW[32], szX, szY;
const int p2 = 4194304;
int* vp, * xp;
bool bit;
 
struct poz {
    int val, i;
}a[1000001], x[1000001], y[1000001];
 
bitset <1000001> b;
 
int main()
{
    int maxi = 0;
 
    for (int i = 0; i <= 30; i++)
        POW[i] = (1 << i);
 
    fin >> n;
 
    for (int i = 1; i <= n; i++)
        fin >> v[i], maxi = max(maxi, v[i]);
 
    int stop = ceil(log2(maxi)) + 1, l, r, m, poz1, poz2, poz;
    int res = 0, downLim, upLim, aux, sz, i;
 
    for (int i = 1; i <= n; i++)
        a[i].i = i, a[i].val = 0;
 
    for (int k = 0; k <= stop; k++)
    {
        bit = false;
        vp = v;
        vp++;
 
        xp = X;
        xp++;
 
        szX = szY = 0;
 
        for (i = 1; i <= n; i++)
        {
            if (*vp & 1)
                *xp += POW[k], b[i] = true;
            else
                b[i] = false;
 
            *vp >>= 1;
 
            vp++;
            xp++;
        }
 
        for (i = 1; i <= n; i++)
            if (b[a[i].i])
                a[i].val += POW[k], y[++szY] = a[i];
            else
                x[++szX] = a[i];
 
        for (i = 1; i <= szX; i++)
            a[i] = x[i];
 
        for (int i = 1; i <= szY; i++)
            a[szX + i] = y[i];
 
        aux = (1 << k) + (1 << (k + 1));
        downLim = POW[k];
        upLim = POW[k + 1] - 1;
 
        for (int i = 1; i <= n; i++)
        {
            poz = -1;
            l = i, r = n;
 
            while (l <= r)
            {
                m = (l + r) >> 1;
 
                if (a[i].val + a[m].val >= aux)
                {
                    poz = m;
                    r = m - 1;
                }
                else
                    l = m + 1;
            }
 
            if (poz != -1)
                bit ^= (n - poz + 1) & 1;
 
            poz1 = -1;
 
            l = i, r = n;
 
            if (poz != -1)
                r = poz - 1;
 
            while (l <= r)
            {
                m = (l + r) >> 1;
 
                if (a[i].val + a[m].val >= downLim)
                {
                    poz1 = m;
                    r = m - 1;
                }
                else
                    l = m + 1;
            }
 
            if (poz1 == -1 || a[i].val + a[poz1].val > upLim)
                continue;
 
            l = poz1, r = n;
 
            if (poz != -1)
                r = poz - 1;
 
            while (l <= r)
            {
                m = (l + r) >> 1;
 
                if (a[i].val + a[m].val <= upLim)
                {
                    poz2 = m;
                    l = m + 1;
                }
                else
                    r = m - 1;
            }
 
            bit ^= (poz2 - poz1 + 1) & 1;
        }
 
        if (bit)
            res += POW[k];
    }
 
    fout << res;
 
    return 0;
}

Compilation message

xorsum.cpp: In function 'int main()':
xorsum.cpp:264:39: warning: unused variable 'sz' [-Wunused-variable]
  264 |     int res = 0, downLim, upLim, aux, sz, i;
      |                                       ^~
xorsum.cpp: In member function 'char Input::read()':
xorsum.cpp:14:18: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |             fread(t, 1, sz, stdin);
      |             ~~~~~^~~~~~~~~~~~~~~~~
xorsum.cpp: In function 'int main()':
xorsum.cpp:371:26: warning: 'poz2' may be used uninitialized in this function [-Wmaybe-uninitialized]
  371 |             bit ^= (poz2 - poz1 + 1) & 1;
      |                     ~~~~~^~~~~~
# Verdict Execution time Memory Grader output
1 Correct 8 ms 464 KB Output is correct
2 Correct 9 ms 504 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1103 ms 29776 KB Output is correct
2 Correct 1026 ms 32156 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1103 ms 29776 KB Output is correct
2 Correct 1026 ms 32156 KB Output is correct
3 Execution timed out 1646 ms 33484 KB Time limit exceeded
4 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 8 ms 464 KB Output is correct
2 Correct 9 ms 504 KB Output is correct
3 Correct 237 ms 4296 KB Output is correct
4 Correct 230 ms 4188 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 8 ms 464 KB Output is correct
2 Correct 9 ms 504 KB Output is correct
3 Correct 1103 ms 29776 KB Output is correct
4 Correct 1026 ms 32156 KB Output is correct
5 Execution timed out 1646 ms 33484 KB Time limit exceeded
6 Halted 0 ms 0 KB -