Longest Common Substring
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public int longestCommonSubstring(String A, String B) { // write your code here int len = 0; String tp = ""; if (A.length() < B.length()) { tp = B; B = A; A = tp; } for (int i = 0; i < A.length(); ++i) { int mLen= 0; for (int j = 0; j < B.length() && i + j < A.length(); ++j) { if (A.charAt(i + j) == B.charAt(j)) { mLen++; if (mLen > len) len = mLen; } else { mLen = 0; } } } return len; }
更简洁的解法:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
int longestCommonSubstring(string &A, string &B) { // write your code here int lenA = A.length(); int lenB = B.length(); int mLen = 0; for (int i = 0; i < lenA; ++i) { for (int j = 0; j < lenB; ++j) { int len = 0; while (i + len < lenA && j + len < lenB && A[i + len] == B[j + len]) { ++len; if (len > mLen) { mLen = len; } } } } return mLen; }
Longest Common Prefix
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public String longestCommonPrefix(String[] strs) { if (strs == null || strs.length == 0) return ""; String pre = strs[0]; for (int i = 1; i < strs.length; ++i) { String tmp = ""; for (int j = 0; j < strs[i].length() && j < pre.length(); ++j) { if (strs[i].charAt(j) == pre.charAt(j)) { tmp += strs[i].charAt(j); } else { break; } } pre = tmp; } return pre; }
String to Integer(atoi)
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public int atoi(String str) { // write your code here int INT_MAX = 2147483647; int INT_MIN = -2147483648; int ret = 0; int sign = 1; if (str == null || str.length() == 0) return 0; int i = 0; while (str.charAt(i) == ' ') { ++i; } if (str.charAt(i) == '-') { sign = -1; ++i; } else if (str.charAt(i) == '+') { sign = 1; ++i; } for (; i < str.length(); ++i) { if (str.charAt(i) == ' ') continue; if (str.charAt(i) < '0' || str.charAt(i) > '9') return ret * sign; ret = ret * 10 + (str.charAt(i) - '0'); } ret *= sign; if (sign > 0 && ret < 0) return INT_MAX; if (sign < 0 && ret > 0) return INT_MIN; return ret; }
总想把每一篇文章精雕细琢之后以完美的面貌示人,就像演员在演出前都要彩排,总想准备好之后再去展现精彩的一面,但人生的每一刻都是精彩的,就算现在还不完善也要发出来,作为自己一直在学习的一种见证。