Cow Patterns poj 3167 (hash解法)

围观了叉姐的代码，hash对于解串类题目真的好灵活， 又涨姿势了 ==。

#include <iostream>#include <cstdio>#include <cstdlib>#include <cmath>#include <queue>#include <algorithm>#include <vector>#include <cstring>#include <stack>#include <cctype>#include <utility>   #include <map>#include <string>  #include <climits> #include <set>#include <string>    #include <sstream>#include <utility>   #include <ctime>#include <bitset>using std::priority_queue;using std::vector;using std::swap;using std::stack;using std::sort;using std::max;using std::min;using std::pair;using std::map;using std::string;using std::cin;using std::cout;using std::set;using std::queue;using std::string;using std::stringstream;using std::make_pair;using std::getline;using std::greater;using std::endl;using std::multimap;using std::deque;using std::unique;using std::lower_bound;using std::random_shuffle;using std::bitset;using std::upper_bound;using std::multiset;typedef long long LL;typedef unsigned long long ULL;typedef unsigned UN;typedef pair<int, int> PAIR;typedef multimap<int, int> MMAP;typedef LL TY;typedef long double LF;const int MAXN(100010);const int MAXM(55);const int MAXE(200010);const int MAXK(6);const int HSIZE(13131);const int SIGMA_SIZE(26);const int MAXH(20);const int INFI((INT_MAX-1) >> 1);const ULL BASE(31);const LL LIM(1e13);const int INV(-10000);const int MOD((1 << 30)-1);const double EPS(1e-7);const LF PI(acos(-1.0));template<typename T> inline void checkmax(T &a, T b){if(b > a) a = b;}template<typename T> inline void checkmin(T &a, T b){if(b < a) a = b;}template<typename T> inline T ABS(const T &a){return a < 0? -a: a;}ULL hash1[30], hash2[30];int arr1[100010], arr2[25010];int ans[100010], ca;int main(){int n, K, s;while(~scanf("%d%d%d", &n, &K, &s)){for(int i = 1; i <= n; ++i) scanf("%d", arr1+i);for(int i = 1; i <= K; ++i) scanf("%d", arr2+i);if(n < K){printf("0\n");continue;}ULL sub = 1;for(int i = 1; i < K; ++i) sub *= BASE;memset(hash2, 0, sizeof(hash2));for(int i = 1; i <= K; ++i){for(int j = 0; j < s; ++j) hash2[j] *= BASE;++hash2[arr2[i]-1];}memset(hash1, 0, sizeof(hash1));for(int i = 1; i < K; ++i){for(int j = 0; j < s; ++j) hash1[j] *= BASE;++hash1[arr1[i]-1];}ca = 0;for(int i = K; i <= n; ++i){for(int j = 0; j < s; ++j) hash1[j] *= BASE;++hash1[arr1[i]-1];int t1 = s-1, t2 = s-1;while(true){while(t1 >= 0 && hash1[t1] == 0) --t1;while(t2 >= 0 && hash2[t2] == 0) --t2;if(t1 == -1 && t2 == -1) break;if(t1 == -1 || t2 == -1) break;if(hash1[t1] != hash2[t2]) break;--t1;--t2;}if(t1 == -1 && t2 == -1) ans[ca++] = i-K+1;hash1[arr1[i-K+1]-1] -= sub;}printf("%d\n", ca);for(int i = 0; i < ca; ++i) printf("%d\n", ans[i]);}return 0;}