Codeforces 282E. Sausage Maximization Trie

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Give the number of N, let you find a prefix and a suffix, they are different or complete after the maximum, the prefix and suffix are different or derived, can be empty, as empty when the 0 count. Prefix suffixes are not overwritten.

This question is good God, unexpectedly is trie tree ...

First, the XOR of all numbers is used as the initial suffix and the initial prefix is 0. Then insert the prefix in the dictionary tree, in the suffix to find, find, from the high to low, if the suffix of the I bit is 0, then look for the dictionary tree in this bit there is no 1, there are 1 to 1 of the road to find, not only to 0 that road to find.

See the code specifically.

#include <iostream>#include<vector>#include<cstdio>#include<cstring>#include<algorithm>#include<cmath>#include<map>#include<Set>#include<string>#include<queue>#include<stack>#include<bitset>using namespacestd;#definePB (x) push_back (x)#definell Long Long#defineMK (x, y) make_pair (x, y)#defineLson L, M, rt<<1#defineMem (a) memset (a, 0, sizeof (a))#defineRson m+1, R, rt<<1|1#defineMem1 (a) memset (a,-1, sizeof (a))#defineMEM2 (a) memset (a, 0x3f, sizeof (a))#defineRep (i, N, a) for (int i = A; i<n; i++)#defineFi first#defineSe Secondtypedef pair<int,int>PLL;Const DoublePI = ACOs (-1.0);Const DoubleEPS = 1e-8;Const intMoD = 1e9+7;Const intINF =1061109567;Const intdir[][2] = { {-1,0}, {1,0}, {0, -1}, {0,1} };structtrie{Trie*next[2]; Trie () {next[0] = next[1] =NULL; }};ll num[100005], top = +; Trie*root =NewTrie ();voidAdd (ll val) {Trie*p =Root;  for(inti = top-1; i>=0; i--) {        intTMP = val>>i&1; if(!p->next[tmp]) p-&GT;NEXT[TMP] =NewTrie (); P= p->Next[tmp]; }}ll query (ll val) {Trie*p =Root; LL ret=0;  for(inti = top-1; i>=0; i--) {        intTMP = val>>i&1; if(p->next[tmp^1]) {ret|= 1ll<<i; TMP^=1; } P= p->Next[tmp]; }    returnret;}intMain () {intN; ll prefix=0, suffix =0, ans =0; CIN>>N;  for(inti =1; i<=n; i++) {cin>>Num[i]; Suffix^=Num[i]; }     for(inti =1; i<=n+1; i++) {Add (prefix); Ans=max (ans, query (suffix)); if(i<=N) {prefix^=Num[i]; Suffix^=Num[i]; }} cout<<ans<<Endl; return 0;}

Codeforces 282E. Sausage Maximization Trie