UVa 141-the Spot Game

Title: Give you a n*n form, two people take turns to operate, each time in a position to put or win a pawn;

If a state, before it appears, then the other wins, ask who wins, if no one wins, output draw.

Analysis: DS, data structure, hash function, state compression.

Each row is stored in a single bit, a one-dimensional array represents a state, and a hash table is used to store the lookup.

Description: Note that the rotated State is considered to be the same.

#include <algorithm> #include <iostream> #include <cstdlib> #include <cstring> #include < Cstdio> #include <cmath>using namespace std;//hash_definetypedef struct Node0{long a[50];node0 *next;} hnode;hnode* hash_head[100];hnode hash_node[100];int hash_size;void hash_init () {hash_size = 0;memset (hash_node, 0, Siz EOF (Hash_node)); memset (hash_head, 0, sizeof (hash_head));} void copy (int a[][50], int b[][50], int n) {for (int i = 0; i < n; + + i) for (int j = 0; J < N; + + j) A[i][j] = B[i ][J];} void over (int a[][50], int. B[][50], int n) {for (int i = 0; i < n; + + i) for (int j = 0; J < N; + + j) A[j][i] = B[n -1-I][J];}  int tem1[50][50],tem2[50][50];int hash_insert (int a[][50], int n) {copy (tem1, A, n), int sum = 0;for (int k = 0; k < 4; + + K) {Over (tem2, TEM1, n); copy (Tem1, TEM2, n); sum = 0;for (int i = 0; i < n; + + i) {hash_node[hash_size]. A[i] = 0;for (int j = 0; J < N; + + j) {Hash_node[hash_size]. A[i] + = Tem2[i][j]<<j;sum = (sum+TEM2[I][J])%100;}} for (hnode* p = hash_head[sum]; p; p = p->next) {int flag = 0;for (int i = 0; i < n; + + i) if (p->a[i]! = Hash _node[hash_size]. A[i]) {flag = 1;break;} if (!flag) return 1;}} Hash_node[hash_size].next = hash_head[sum];hash_head[sum] = &hash_node[hash_size ++];return 0; }//hash_endint Maps[50][50];int Main () {int N,x,y;char ch;while (~scanf ("%d", &n) && N) {memset (maps, 0, Sizeo F (maps)); Hash_init (); int flag = 0;for (int i = 1; I <= 2*n; + + i) {scanf ("%d%d%c", &x,&y,&ch); if (ch = = ' + ') {if (maps[x-1][y-1] &&!flag) flag = i;else Maps[x-1][y-1] = 1;} else {if (!maps[x-1][y-1] &&!flag) flag = i;else Maps[x-1][y-1] = 0;} if (Hash_insert (maps, n) &&!flag) flag = i;}    if (!flag) printf ("draw\n"), Else printf ("Player%d wins on move%d\n", 1+flag%2,flag);} return 0;}

UVa 141-the Spot Game