Submission #874573

#	Time	Username	Problem	Language	Result	Execution time	Memory
874573		sleepntsheep	XOR (IZhO12_xor)	C++17	0 / 100	9 ms	812 KiB

xor

#include <assert.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>

#define N 250000
#define M 7000000

int n, x, z, a[N+1], zz;
int A[M], C[M][2], alloc = 1;

int min(int a, int b) { return a < b ? a : b; }
int max(int a, int b) { return a > b ? a : b; }

void insert(int v, int x, int j, int i)
{
    int b = (x >> j) & 1;
    A[v] = max(A[v], i);
    if (j)
    {
        if (!C[v][b]) C[v][b] = ++alloc;
        insert(C[v][b], x, j-1, i);
        A[v] = max(A[v], max(A[C[v][0]], A[C[v][1]]));
    }
}

int query(int v, int x, int y, int j)
{
    if (y <= 0) return A[v];
    int b = (x >> j) & 1, z = -1;
    if (j)
    {
        if (C[v][b^1] && A[C[v][b^1]] > z) z = max(z, query(C[v][b^1], x, y - (1 << j), j-1));
        if ((1u << j) > y)
            if (C[v][b] && A[C[v][b]] > z) z = max(z, query(C[v][b], x, y, j-1));
    }
    return z;
}

int main(void)
{
    scanf("%d%d", &n, &x);
    for (int i = 1; i <= n; ++i) scanf("%d", a+i), a[i] ^= a[i-1], insert(1, a[i], 31, i);
    for (int b, i = 0; i < n; ++i) if ((b = query(1, a[i], x, 31) - i) > z)
        z = b, zz = i + 1;
    printf("%d %d", zz, z);

    return 0;
}

Compilation message (stderr)

xor.cpp: In function 'int query(int, int, int, int)':
xor.cpp:35:23: warning: comparison of integer expressions of different signedness: 'unsigned int' and 'int' [-Wsign-compare]
   35 |         if ((1u << j) > y)
      |             ~~~~~~~~~~^~~
xor.cpp: In function 'int main()':
xor.cpp:43:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   43 |     scanf("%d%d", &n, &x);
      |     ~~~~~^~~~~~~~~~~~~~~~
xor.cpp:44:39: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |     for (int i = 1; i <= n; ++i) scanf("%d", a+i), a[i] ^= a[i-1], insert(1, a[i], 31, i);
      |                                  ~~~~~^~~~~~~~~~~

• Subtask 1: 0 / 100