leetcode_171 Excel Sheet Column Number
题目：
Related to question Excel Sheet Column Title
Given a column title as appear in an Excel sheet, return its corresponding column number.
解法：
class Solution {
public:
int titleToNumber(string s)
{
int num = 0;
int length = s.size();
for(int i = length - 1; i >= 0; --i)
{
num += pow(26, (length - 1 - i)) * (s[i] - 'A' + 1);
}
return num;
}
};题目：
Implement strStr().
Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.
解法：
class Solution {
public:
int strStr(string haystack, string needle)
{
int length_h = haystack.size();
int length_n = needle.size();
if(length_h < length_n)
return -1;
if(length_h == 0 || length_n == 0)
return 0;
int i = 0;
while(i <= length_h - length_n)
{
int j = 0;
int tmp = i;
while(j < length_n)
{
if(haystack[tmp] != needle[j])
break;
else
{
++tmp;
++j;
if(j == length_n)
return i;
}
}
++i;
}
return -1;
}
};版权声明：本文为博主原创文章，未经博主允许不得转载。
leetcode_171 Excel Sheet Column Number & leetcode_28 Implement strStr()
原文：http://blog.csdn.net/xwchao2014/article/details/47729705