添加 problem 1208

This commit is contained in:
YDZ
2020-01-09 21:51:53 +08:00
parent bc84b89413
commit 3ec36c77ba
3 changed files with 133 additions and 0 deletions

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package leetcode
func equalSubstring(s string, t string, maxCost int) int {
left, right, res := 0, -1, 0
for left < len(s) {
if right+1 < len(s) && maxCost-abs(int(s[right+1]-'a')-int(t[right+1]-'a')) >= 0 {
right++
maxCost -= abs(int(s[right]-'a') - int(t[right]-'a'))
} else {
res = max(res, right-left+1)
maxCost += abs(int(s[left]-'a') - int(t[left]-'a'))
left++
}
}
return res
}

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package leetcode
import (
"fmt"
"testing"
)
type question1208 struct {
para1208
ans1208
}
// para 是参数
// one 代表第一个参数
type para1208 struct {
s string
t string
maxCost int
}
// ans 是答案
// one 代表第一个答案
type ans1208 struct {
one int
}
func Test_Problem1208(t *testing.T) {
qs := []question1208{
question1208{
para1208{"abcd", "bcdf", 3},
ans1208{3},
},
question1208{
para1208{"abcd", "cdef", 3},
ans1208{1},
},
question1208{
para1208{"abcd", "acde", 0},
ans1208{1},
},
question1208{
para1208{"thjdoffka", "qhrnlntls", 11},
ans1208{3},
},
question1208{
para1208{"krrgw", "zjxss", 19},
ans1208{2},
},
}
fmt.Printf("------------------------Leetcode Problem 1208------------------------\n")
for _, q := range qs {
_, p := q.ans1208, q.para1208
fmt.Printf("【input】:%v 【output】:%v\n", p, equalSubstring(p.s, p.t, p.maxCost))
}
fmt.Printf("\n\n\n")
}

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# [1208. Get Equal Substrings Within Budget](https://leetcode.com/problems/get-equal-substrings-within-budget/)
## 题目:
You are given two strings `s` and `t` of the same length. You want to change `s` to `t`. Changing the `i`-th character of `s` to `i`-th character of `t` costs `|s[i] - t[i]|` that is, the absolute difference between the ASCII values of the characters.
You are also given an integer `maxCost`.
Return the maximum length of a substring of `s` that can be changed to be the same as the corresponding substring of `t`with a cost less than or equal to `maxCost`.
If there is no substring from `s` that can be changed to its corresponding substring from `t`, return `0`.
**Example 1:**
Input: s = "abcd", t = "bcdf", maxCost = 3
Output: 3
Explanation: "abc" of s can change to "bcd". That costs 3, so the maximum length is 3.
**Example 2:**
Input: s = "abcd", t = "cdef", maxCost = 3
Output: 1
Explanation: Each character in s costs 2 to change to charactor in t, so the maximum length is 1.
**Example 3:**
Input: s = "abcd", t = "acde", maxCost = 0
Output: 1
Explanation: You can't make any change, so the maximum length is 1.
**Constraints:**
- `1 <= s.length, t.length <= 10^5`
- `0 <= maxCost <= 10^6`
- `s` and `t` only contain lower case English letters.
## 题目大意
给你两个长度相同的字符串s 和 t。将 s 中的第 i 个字符变到 t 中的第 i 个字符需要 |s[i] - t[i]| 的开销(开销可能为 0也就是两个字符的 ASCII 码值的差的绝对值。
用于变更字符串的最大预算是 maxCost。在转化字符串时总开销应当小于等于该预算这也意味着字符串的转化可能是不完全的。如果你可以将 s 的子字符串转化为它在 t 中对应的子字符串,则返回可以转化的最大长度。如果 s 中没有子字符串可以转化成 t 中对应的子字符串,则返回 0。
提示:
- 1 <= s.length, t.length <= 10^5
- 0 <= maxCost <= 10^6
- s 和 t 都只含小写英文字母。
## 解题思路
- 给出 2 个字符串 `s``t` 和一个“预算”,要求把“预算”尽可能的花完,`s` 中最多连续有几个字母能变成 `t` 中的字母。“预算”的定义是:|s[i] - t[i]| 。
- 这一题是滑动窗口的题目,滑动窗口右边界每移动一格,就减少一定的预算,直到预算不能减少,再移动滑动窗口的左边界,这个时候注意要把预算还原回去。当整个窗口把字符 `s``t` 都滑动完了的时候,取出滑动过程中窗口的最大值即为结果。