Codeforces 742B Arpa ' s obvious problem and Mehrdad ' s terrible solution (brute force enumeration)

Test instructions: The number of n is determined, and the number of logarithms is satisfied, Ai^bi = x.

Analysis: Brute force enumeration on the line, the complexity of N.

The code is as follows:

#pragma COMMENT (linker, "/stack:1024000000,1024000000") #include <cstdio> #include <string> #include < cstdlib> #include <cmath> #include <iostream> #include <cstring> #include <set> #include < queue> #include <algorithm> #include <vector> #include <map> #include <cctype> #include < cmath> #include <stack> #define FREOPENR freopen ("In.txt", "R", stdin) #define FREOPENW freopen ("OUT.txt", "W",  STDOUT) using namespace Std;typedef long Long ll;typedef pair<int, int> p;const int inf = 0x3f3f3f3f;const double inf = 0x3f3f3f3f3f3f;const Double PI = ACOs ( -1.0); const double EPS = 1e-8;const int maxn = 1e5 + 5;const int mod = 1e9 + 7;co NST int dr[] = {-1, 1, 0, 0};const int dc[] = {0, 0, 1, -1};const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0 101 "," 0110 "," 0111 "," $ "," 1001 "," 1010 "," 1011 "," 1100 "," 1101 "," 1110 "," 1111 "};int N, m;const int mon[] = {0, 31, 2 8, A, a, a, a, a, a, a, a, 31};const inT monn[] = {0, h, h, N, N, H,, H, H, N, h, 31};inline int Min (int a, int b) {return a < b? A:b;} inline int Max (int a, int b) {return a > b a:b;} inline ll Min (ll A, ll b) {return a < b a:b;} inline ll Max (ll A, ll b) {return a > b a:b;} inline bool Is_in (int r, int c) {return R >= 0 && r < n && C >= 0 && C < m;}    int A[100005];int B[100005];int Main () {LL n, m;        while (scanf ("%i64d%i64d", &n, &m) = = 2) {for (int i = 0; i < n; ++i) scanf ("%d", a+i);        memset (b, 0, sizeof B); LL ans = 0;//if (m = = 0) {//for ()//continue;//} for (int i = n-1; I >= 0;-            -i) {LL t = a[i] ^ m;            if (T < 100005) ans + = b[t];        ++b[a[i]];    } cout << ans << endl; } return 0;}

Codeforces 742B Arpa ' s obvious problem and Mehrdad ' s terrible solution (brute force enumeration)