1460. Make Two Arrays Equal by Reversing Subarrays

Description

You are given two integer arrays of equal length target and arr. In one step, you can select any non-empty subarray of arr and reverse it. You are allowed to make any number of steps.

Return true if you can make arr equal to target or false otherwise.

 

Example 1:

Input: target = [1,2,3,4], arr = [2,4,1,3]
Output: true
Explanation: You can follow the next steps to convert arr to target:
1- Reverse subarray [2,4,1], arr becomes [1,4,2,3]
2- Reverse subarray [4,2], arr becomes [1,2,4,3]
3- Reverse subarray [4,3], arr becomes [1,2,3,4]
There are multiple ways to convert arr to target, this is not the only way to do so.

Example 2:

Input: target = [7], arr = [7]
Output: true
Explanation: arr is equal to target without any reverses.

Example 3:

Input: target = [3,7,9], arr = [3,7,11]
Output: false
Explanation: arr does not have value 9 and it can never be converted to target.

 

Constraints:

  • target.length == arr.length
  • 1 <= target.length <= 1000
  • 1 <= target[i] <= 1000
  • 1 <= arr[i] <= 1000

Solutions

Solution 1

Python Code
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class Solution:
    def canBeEqual(self, target: List[int], arr: List[int]) -> bool:
        target.sort()
        arr.sort()
        return target == arr

Java Code
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class Solution {
    public boolean canBeEqual(int[] target, int[] arr) {
        Arrays.sort(target);
        Arrays.sort(arr);
        return Arrays.equals(target, arr);
    }
}

C++ Code
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class Solution {
public:
    bool canBeEqual(vector<int>& target, vector<int>& arr) {
        sort(target.begin(), target.end());
        sort(arr.begin(), arr.end());
        return target == arr;
    }
};

Go Code
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func canBeEqual(target []int, arr []int) bool {
	sort.Ints(target)
	sort.Ints(arr)
	for i, v := range target {
		if v != arr[i] {
			return false
		}
	}
	return true
}

TypeScript Code
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function canBeEqual(target: number[], arr: number[]): boolean {
    target.sort((a, b) => a - b);
    arr.sort((a, b) => a - b);
    const n = arr.length;
    for (let i = 0; i < n; i++) {
        if (target[i] !== arr[i]) {
            return false;
        }
    }
    return true;
}

Rust Code
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impl Solution {
    pub fn can_be_equal(mut target: Vec<i32>, mut arr: Vec<i32>) -> bool {
        target.sort();
        arr.sort();
        target == arr
    }
}

PHP Code
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class Solution {
    /**
     * @param Integer[] $target
     * @param Integer[] $arr
     * @return Boolean
     */
    function canBeEqual($target, $arr) {
        sort($target);
        sort($arr);
        return $target === $arr;
    }
}

C Code
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bool canBeEqual(int* target, int targetSize, int* arr, int arrSize) {
    int count[1001] = {0};
    for (int i = 0; i < targetSize; i++) {
        count[target[i]]++;
        count[arr[i]]--;
    }
    for (int i = 0; i < 1001; i++) {
        if (count[i] != 0) {
            return false;
        }
    }
    return true;
}

Solution 2

Python Code
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class Solution:
    def canBeEqual(self, target: List[int], arr: List[int]) -> bool:
        return Counter(target) == Counter(arr)

Java Code
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class Solution {
    public boolean canBeEqual(int[] target, int[] arr) {
        int[] cnt1 = new int[1001];
        int[] cnt2 = new int[1001];
        for (int v : target) {
            ++cnt1[v];
        }
        for (int v : arr) {
            ++cnt2[v];
        }
        return Arrays.equals(cnt1, cnt2);
    }
}

C++ Code
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class Solution {
public:
    bool canBeEqual(vector<int>& target, vector<int>& arr) {
        vector<int> cnt1(1001);
        vector<int> cnt2(1001);
        for (int& v : target) ++cnt1[v];
        for (int& v : arr) ++cnt2[v];
        return cnt1 == cnt2;
    }
};

Go Code
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func canBeEqual(target []int, arr []int) bool {
	cnt1 := make([]int, 1001)
	cnt2 := make([]int, 1001)
	for _, v := range target {
		cnt1[v]++
	}
	for _, v := range arr {
		cnt2[v]++
	}
	for i, v := range cnt1 {
		if v != cnt2[i] {
			return false
		}
	}
	return true
}

TypeScript Code
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function canBeEqual(target: number[], arr: number[]): boolean {
    const n = target.length;
    const count = new Array(1001).fill(0);
    for (let i = 0; i < n; i++) {
        count[target[i]]++;
        count[arr[i]]--;
    }
    return count.every(v => v === 0);
}

Rust Code
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impl Solution {
    pub fn can_be_equal(mut target: Vec<i32>, mut arr: Vec<i32>) -> bool {
        let n = target.len();
        let mut count = [0; 1001];
        for i in 0..n {
            count[target[i] as usize] += 1;
            count[arr[i] as usize] -= 1;
        }
        count.iter().all(|v| *v == 0)
    }
}

Solution 3

Python Code
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class Solution:
    def canBeEqual(self, target: List[int], arr: List[int]) -> bool:
        cnt = [0] * 1001
        for a, b in zip(target, arr):
            cnt[a] += 1
            cnt[b] -= 1
        return all(v == 0 for v in cnt)

Java Code
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class Solution {
    public boolean canBeEqual(int[] target, int[] arr) {
        int[] cnt = new int[1001];
        for (int v : target) {
            ++cnt[v];
        }
        for (int v : arr) {
            if (--cnt[v] < 0) {
                return false;
            }
        }
        return true;
    }
}

C++ Code
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class Solution {
public:
    bool canBeEqual(vector<int>& target, vector<int>& arr) {
        vector<int> cnt(1001);
        for (int& v : target) ++cnt[v];
        for (int& v : arr)
            if (--cnt[v] < 0) return false;
        return true;
    }
};

Go Code
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func canBeEqual(target []int, arr []int) bool {
	cnt := make([]int, 1001)
	for _, v := range target {
		cnt[v]++
	}
	for _, v := range arr {
		cnt[v]--
		if cnt[v] < 0 {
			return false
		}
	}
	return true
}