// -------------------- Includes -------------------- //
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <stdio.h>
#include <cstdlib>
#include <stdlib.h>
#include <array>
#include <string>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <math.h>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <bitset>
#include <list>
#include <iterator>
#include <numeric>
#include <complex>
#include <tuple>
#include <utility>
#include <cassert>
#include <assert.h>
#include <climits>
#include <limits.h>
#include <ctime>
#include <time.h>
#include <random>
#include <chrono>
#include <fstream>
using namespace std;
// -------------------- Typedefs -------------------- //
typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;
// -------------------- Defines -------------------- //
#define pr pair
#define mpr make_pair
#define ff first
#define ss second
#define mset multiset
#define mmap multimap
#define uset unordered_set
#define umap unordered_map
#define umset unordered_multiset
#define ummap unordered_multimap
#define pqueue priority_queue
#define sz(x) (int((x).size()))
#define len(x) (int((x).length()))
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define clr(x) (x).clear()
#define pf push_front
#define pb push_back
#define popf pop_front
#define popb pop_back
#define ft front
#define bk back
#define lb lower_bound
#define ub upper_bound
#define bs binary_search
// -------------------- Constants -------------------- //
const int MAX = int(1e9 + 5);
const ll MAXL = ll(1e18 + 5);
const ll MOD = ll(1e9 + 7);
const ll MOD2 = ll(998244353);
// -------------------- Functions -------------------- //
void fastio()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
return;
}
void precision(int x)
{
cout.setf(ios::fixed | ios::showpoint);
cout.precision(x);
return;
}
ll gcd(ll a, ll b)
{
if (a > b) {
swap(a, b);
}
if (a == 0) {
return b;
}
if (a == b) {
return a;
}
return gcd(b % a, a);
}
ll lcm(ll a, ll b)
{
return a / gcd(a, b) * b;
}
bool is_prime(ll a)
{
int i;
for (i = 2; i * i <= a; i++) {
if (a % ll(i) == 0) {
return false;
}
}
return true;
}
bool is_square(ll a)
{
ll b = ll(sqrt(a));
return (b * b == a);
}
bool is_cube(ll a)
{
ll b = ll(cbrt(a));
return (b * b * b == a);
}
int digit_sum(ll a)
{
int sum = 0;
while (a) {
sum += int(a % 10);
a /= 10;
}
return sum;
}
ll binpow(ll a, int b)
{
ll ans = 1;
while (b) {
if ((b & 1) == 1) {
ans *= a;
}
b >>= 1;
a *= a;
}
return ans;
}
ll binpow_by_mod(ll a, ll b, ll mod)
{
ll ans = 1;
while (b) {
if ((b & 1) == 1) {
ans *= a;
ans %= mod;
}
b >>= 1;
a *= a;
a %= mod;
}
return ans;
}
ll factorial(int a)
{
int i;
ll ans = 1;
for (i = 2; i <= a; i++) {
ans *= ll(i);
}
return ans;
}
ll factorial_by_mod(int a, ll mod)
{
int i;
ll ans = 1;
for (i = 2; i <= a; i++) {
ans *= ll(i);
ans %= mod;
}
return ans;
}
// -------------------- Solution -------------------- //
const int N = 1005;
int a[N];
int n;
set<int> st;
vector<pr<int, int>> ans;
void solve()
{
int i, j;
int s;
cin >> n >> s;
for (i = 1; i <= n; i++) {
cin >> a[i];
}
if (s == 1) {
}
else {
for (i = 19; i >= 0; i--) {
clr(st);
for (j = 1; j <= n; j++) {
if ((a[j] & (1 << i))) {
st.insert(j);
}
}
/*for (auto x : st) {
cout << x << ' ';
}
cout << endl;*/
while (!st.empty()) {
j = (*st.begin());
st.erase(st.begin());
if (j == n) {
break;
}
if (st.find(j + 1) == st.end()) {
st.insert(j);
st.insert(j + 1);
ans.pb(mpr(j + 1, j));
a[j + 1] ^= a[j];
//cout << j + 1 << ' ' << j << ' ' << i << endl;
}
else {
st.insert(j + 1);
ans.pb(mpr(j, j + 1));
a[j] ^= a[j + 1];
//cout << j << ' ' << j + 1 << ' ' << i << endl;
}
}
}
cout << sz(ans) << endl;
for (i = 0; i < sz(ans); i++) {
cout << ans[i].ff << ' ' << ans[i].ss << endl;
}
}
return;
}
void precalc()
{
return;
}
int main()
{
fastio();
precalc();
int tests = 1, tc;
//cin >> tests;
for (tc = 1; tc <= tests; tc++) {
solve();
}
//cout << db(clock()) / CLOCKS_PER_SEC << endl;
return 0;
}
/*
# # # # # # # # # # # # # # # # #
# # # # # # # # # #
# # # # # # # # # # # # #
# # # # # # # # # # # #
# # # # # # # # # # # # # #
*/
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
204 KB |
Unexpected end of file - int32 expected |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
204 KB |
Unexpected end of file - int32 expected |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
1 ms |
204 KB |
Not sorted |
| 2 |
Halted |
0 ms |
0 KB |
- |
