LeetCode: Wildcard Matching

这题第一次做用dfs，结果过不了large，网上寻找到答案，这里s和p指针是会变的，重点处理ptr遇到*的时候，这个时候s和p都往后挪，p重新定位，看s后面和p后面的是不是match，如果不match则s向后移，再继续看后面的是不是match，直到s到底为止，这里str和ptr是浮动指针，s和p相对静止，记录前一个邵点。

 1 class Solution {
 2 public:
 3     bool isMatch(const char *s, const char *p) {
 4         // Start typing your C/C++ solution below
 5         // DO NOT write int main() function
 6         bool star = false;
 7         const char *str, *ptr;
 8         for (str = s, ptr = p; *str != '\0'; str++, ptr++) {
 9             if (*ptr == '*') {
10                 star = true;
11                 s = str, p = ptr;
12                 while (*p == '*') p++;
13                 if (*p == '\0') return true;
14                 str = s-1, ptr = p-1;
15             }
16             else if (*ptr == '?') continue;
17             else {
18                 if (*str != *ptr) {
19                     if (!star) return false;
20                     s++;
21                     str = s-1, ptr = p-1;
22                 }
23             }
24         }
25         while (*ptr == '*') ptr++;
26         return *ptr == '\0';
27     }
28 };

while的可能更好懂

 1 class Solution {
 2 public:
 3     bool isMatch(const char *s, const char *p) {
 4         const char *s1, *p1;
 5         s1 = s, p1 = p;
 6         bool star = false;
 7         while (*s1 != '\0') {
 8             if (*s1 == *p1 || *p1 == '?') {
 9                 s1++, p1++;
10             }
11             else {
12                 if (*p1 == '*') {
13                     star = true;
14                     p = p1, s = s1;
15                     while (*p == '*') p++;
16                     if (*p == '\0') return true;
17                     p1 = p;
18                 }
19                 else {
20                     if (!star) return false;
21                     s++;
22                     s1 = s, p1 = p;
23                 }
24             }
25         }
26         while (*p1 == '*') p1++;
27         return *p1 == '\0';
28     }
29 };

posted @ 2013-04-23 01:58 ying_vincent 阅读(285) 评论(0) 收藏举报

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