796.rotate-string

Statement

简体中文English

Metadata

• Link: 旋转字符串
• Difficulty: Easy
• Tag: 字符串 字符串匹配

给定两个字符串, s 和 goal。如果在若干次旋转操作之后，s 能变成 goal ，那么返回 true 。

s 的 旋转操作 就是将 s 最左边的字符移动到最右边。 

• 例如, 若 s = 'abcde'，在旋转一次之后结果就是'bcdea' 。

 

示例 1:

输入: s = "abcde", goal = "cdeab"
输出: true

示例 2:

输入: s = "abcde", goal = "abced"
输出: false

 

提示:

• 1 <= s.length, goal.length <= 100
• s 和 goal 由小写英文字母组成

Metadata

• Link: Rotate String
• Difficulty: Easy
• Tag: String String Matching

Given two strings s and goal, return true if and only if s can become goal after some number of shifts on s.

A shift on s consists of moving the leftmost character of s to the rightmost position.

• For example, if s = "abcde", then it will be "bcdea" after one shift.

 

Example 1:

Input: s = "abcde", goal = "cdeab"
Output: true

Example 2:

Input: s = "abcde", goal = "abced"
Output: false

 

Constraints:

• 1 <= s.length, goal.length <= 100
• s and goal consist of lowercase English letters.

Solution

C++

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define endl "\n"
#define fi first
#define se second
#define all(x) begin(x), end(x)
#define rall rbegin(a), rend(a)
#define bitcnt(x) (__builtin_popcountll(x))
#define complete_unique(a) a.erase(unique(begin(a), end(a)), end(a))
#define mst(x, a) memset(x, a, sizeof(x))
#define MP make_pair

using ll = long long;
using ull = unsigned long long;
using db = double;
using ld = long double;
using VLL = std::vector<ll>;
using VI = std::vector<int>;
using PII = std::pair<int, int>;
using PLL = std::pair<ll, ll>;

using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
const ll mod = 1e9 + 7;

template <typename T, typename S>
inline bool chmax(T &a, const S &b) {
    return a < b ? a = b, 1 : 0;
}

template <typename T, typename S>
inline bool chmin(T &a, const S &b) {
    return a > b ? a = b, 1 : 0;
}

#ifdef LOCAL
#include <debug.hpp>
#else
#define dbg(...)
#endif
// head

class Solution {
public:
    bool rotateString(string s, string goal) {
        if (s.length() != goal.length()) {
            return false;
        }

        s.insert(s.end(), all(s));

        for (int i = 0; i < goal.length(); i++) {
            if (s.substr(i, goal.length()) == goal) {
                return true;
            }
        }

        return false;
    }
};

#ifdef LOCAL

int main() {
    return 0;
}

#endif

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最后更新: October 11, 2023