LeetCode 383. Ransom Note

Description

Given an arbitrary ransom note string and another string containing letters from all the magazines, write a function that will return true if the ransom note can be constructed from the magazines ; otherwise, it will return false.

Each letter in the magazine string can only be used once in your ransom note.

Note:

You may assume that both strings contain only lowercase letters.

canConstruct("a", "b") -> false
canConstruct("aa", "ab") -> false
canConstruct("aa", "aab") -> true

Analysis

统计

magazine

中各小写字母出现的次数，然后供

ransomNote

使用，若发现某字母不足，则返回

false

；函数未在循环中途

return

，则说明为

true

。

Code

class Solution {
public:
bool canConstruct(string ransomNote, string magazine) {
int maga[26] = {0};
for (char c : magazine)
maga[c- 97]++;
for (char c : ransomNote)
if (--maga[c - 97] < 0)
return false;
return true;
}
};

Appendix

Link: https://leetcode.com/problems/ransom-note/

Run Time: 19ms, beats 97.57%