解题报告:问Alice的串是否能通过反转以及整除10的操作达到和Bob的串一样。相当于Bob的串只要是Alice的串的子串Alice就能赢。特别的,Bob的串为0的话Alice一定能赢!
Code:
#include <stdio.h>
#include <string.h>
using namespace std;
const int maxn = (int)1e5+5;
char sa[maxn],pattern[maxn],saa[maxn];
int prefix[maxn];
void mystr(char str[], int n) {
int i,j;
char tmp;
i = 0;
j = n-1;
while (i < j) {
tmp = str[i];
str[i] = str[j];
str[j] = tmp;
i++;
j--;
}
}
void get_prefix_table (int n) {
int i = 0, len = -1;
prefix[0] = -1;
while (i < n) {
if(len == -1 || pattern[i] == pattern[len]) {
i++;
len++;
prefix[i] = len;
}else {
len = prefix[len];
}
}
}
int kmp_search (int n, int m, char Tmp[]) {
int ans = 0, i = 0, j = 0;
while (i < n) {
if(j == -1 || Tmp[i] == pattern[j]) {
i++;
j++;
}else {
j = prefix[j];
}
if(j == m) {
ans++;
j = prefix[j];
}
}
return ans;
}
int main() {
int T;
scanf("%d", &T);
while (T--) {
getchar();
scanf("%s%s", sa, pattern);
int l1 = strlen(sa);
int l2 = strlen(pattern);
if (l1 < l2) {
printf("Bob\n");
continue;
}
strcpy(saa, sa);
mystr(saa, l1);
get_prefix_table (l2);
int k1 = kmp_search(l1, l2, sa);
int k2 = kmp_search(l1, l2, saa);
if (k1 != 0 || k2 != 0 || l2 == 1 && pattern[0] == '0') {
printf("Alice\n");
} else {
printf("Bob\n");
}
}
return 0;
}