HDU1880 简单字符串哈希

给定多个魔咒以及对应的效果，要求对于后面的魔咒或效果，及时给出对应的效果或魔咒。

建立两张哈希表直接哈希就可以了。输入需要稍微处理一下。哈希函数计算出来的值要保证是正的，否则读数组会出错。

#include <iostream>#include <cstdio>#include <algorithm>using namespace std;const int N = 100010;const int H = 100007;struct Node{char que[25];char ans[85];int next;};Node nodeA[N], nodeB[N];int curA, curB;int hashTableA[N], hashTableB[N];void initHash(){for (int i = 0; i < H; ++i) {hashTableA[i] = -1;hashTableB[i] = -1;}curA = 0;curB = 0;}unsigned int getHash(char* str){unsigned int seed = 131;unsigned int hash = 0;while (*str){hash = hash * seed + *str++;}return (hash & 0x7fffffff) % H;}void insertHash(char* que, char* ans){unsigned int h;h = getHash(que);strcpy(nodeA[curA].que, que);strcpy(nodeA[curA].ans, ans);nodeA[curA].next = hashTableA[h];hashTableA[h] = curA;++curA;h = getHash(ans);strcpy(nodeB[curB].que, que);strcpy(nodeB[curB].ans, ans);nodeB[curB].next = hashTableB[h];hashTableB[h] = curB;++curB;}int searchHashA(char* que){unsigned int h = getHash(que);int next = hashTableA[h];while (next != -1){if (strcmp(que, nodeA[next].que) == 0) return next;next = nodeA[next].next;}return -1;}int searchHashB(char* ans){unsigned int h = getHash(ans);int next = hashTableB[h];while (next != -1){if (strcmp(ans, nodeA[next].ans) == 0) return next;next = nodeB[next].next;}return -1;}int main(){char str[120], que[25], ans[85], qlen, alen;int n, res;initHash();while (gets(str)){if (str[0] == '@') break;qlen = 0;for (int i = 1; str[i] != ']'; ++i){que[qlen++] = str[i];}que[qlen] = 0;alen = 0;for (int i = qlen + 3; str[i] != 0; ++i){ans[alen++] = str[i];}ans[alen] = 0;insertHash(que, ans);}scanf("%d", &n);getchar();while (n--){gets(str);if (str[0] == '['){qlen = strlen(str);str[qlen - 1] = 0;res = searchHashA(str + 1);if (res == -1) printf("what?\n");else printf("%s\n", nodeA[res].ans);}else{alen = strlen(str);res = searchHashB(str);if (res == -1) printf("what?\n");else printf("%s\n", nodeB[res].que);}}system("pause");return 0;}