HDU 5792 World is exploding (discretization + tree Array)

Test instructions: Given n number, let you count a < b && C < d && A! = b! = c! = d && Aa < Ab && Ac > Ad.

Analysis: First, the number of the given is too large, first to be discretized, and then first to calculate AA < Ab and Ac > Ad. This can be solved with a tree-like array, a forward, a reverse, and then four kinds of numbers, and then subtract, just fine.

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> #include <sstream> #include <list> #include <assert.h> #include < Bitset> #define DEBUG () puts ("++++"); #define GCD (A, B) __gcd (A, b) #define Lson l,m,rt<<1#define Rson m+1,r,rt <<1|1#define fi first#define se second#define pb push_back#define sqr (x) ((x) * (x)) #define MS (A, b) memset (A, C, Sizeo f a)//#define SZ size () #define PU push_up#define PD push_down#define CL Clear () #define ALL 1,n,1#define for (x,n) for (int i = (x); I < (n); ++i) #define FREOPENR freopen ("In.txt", "R", stdin) #define FREOPENW freopen ("OUT.txt", "w", stdout) using namespace std; typedef long Long Ll;typedef unsigned longLong Ull;typedef pair<int, int> p;const int inf = 0x3f3f3f3f;const LL LNF = 1e15;const Double INF = 1e20;const Doubl E PI = ACOs ( -1.0); const double EPS = 1e-8;const int maxn = 5e4 + 100;const int mod = 7;const int dr[] = {-1, 0, 1, 0};cons t int dc[] = {0, 1, 0, -1};const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "10 "1010", "1011", "1100", "1101", "1110", "1111"};int N, m;const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31  , 31};const int monn[] = {0, d, D, D, D,, D, D,, D,, 31};inline bool is_in (int r, int c) {return R >= 0 && r < n && C >= 0 && C < m;} vector<int> v;int a[maxn];int sum[2][maxn<<1];int lowbit (int x) {return-x&x;}    void Add (int pos, int x) {while (x <= N) {++sum[pos][x];  x + = Lowbit (x);  }}int query (int pos, int x) {int ans = 0;    while (x) {ans + = sum[pos][x];  X-= Lowbit (x); } return ans; int GetPos (int x) {returnLower_bound (V.begin (), V.end (), X)-V.begin ();    int B[MAXN], C[MAXN], D[MAXN], E[maxn];int main () {while (scanf ("%d", &n) = = 1) {v.cl; MS (sum, 0);    V.PB (-1);      for (int i = 0; i < n; ++i) {scanf ("%d", a+i);    V.PB (A[i]);    } sort (V.begin (), V.end ());    V.erase (Unique (V.begin (), V.end ()), V.end ());    LL ans = 0;    LL tmp1 = 0, tmp2 = 0;    LL Tmp3 = 0, Tmp4 = 0, tmp5 = 0;      for (int i = 0; i < n; ++i) {int pos = GetPos (A[i]);      B[i] = query (0, pos-1); TMP1 + = B[i];      Min C[i] = i-query (0, POS);      Tmp3 + = (LL) b[i] * C[i];    Add (0, POS);      } for (int i = n-1; I >= 0; i.) {int pos = GetPos (A[i]);      D[i] = query (1, pos-1);  TMP2 + = D[i];      Right min e[i] = (n-i-1)-Query (1, POS);      Tmp4 + = (LL) d[i] * E[i]; Tmp4 + = (n-i-1)-Query (1, POS);    Right Max Add (1, POS);    } LL tmp6 = 0;      for (int i = 0; i < n; ++i) {TMP5 + = (LL) c[i] * E[i];    TMP6 + = (LL) b[i] * D[i]; } ans = tmp1 * TMP2-TMP3-TMP4-TMP5-TMP6;  printf ("%i64d\n", ans); } return 0;}

　　

HDU 5792 World is exploding (discretization + tree Array)