• # For Solution

Given an array of digit strings `nums` and a digit string `target`, return the number of pairs of indices `(i, j)` (where `i != j`) such that the concatenation of `nums[i] + nums[j]` equals `target`. Number of Pairs of Strings With Concatenation Equal to Target solution leetcode

### Number of Pairs of Strings With Concatenation Equal to Target solution leetcode

```Input: nums = ["777","7","77","77"], target = "7777"
Output: 4
Explanation: Valid pairs are:
- (0, 1): "777" + "7"
- (1, 0): "7" + "777"
- (2, 3): "77" + "77"
- (3, 2): "77" + "77"
```

### Number of Pairs of Strings With Concatenation Equal to Target solution leetcode

```Input: nums = ["123","4","12","34"], target = "1234"
Output: 2
Explanation: Valid pairs are:
- (0, 1): "123" + "4"
- (2, 3): "12" + "34"
```

Example 3:

```Input: nums = ["1","1","1"], target = "11"
Output: 6
Explanation: Valid pairs are:
- (0, 1): "1" + "1"
- (1, 0): "1" + "1"
- (0, 2): "1" + "1"
- (2, 0): "1" + "1"
- (1, 2): "1" + "1"
- (2, 1): "1" + "1"
```

### Number of Pairs of Strings With Concatenation Equal to Target solution leetcode

• `2 <= nums.length <= 100`
• `1 <= nums[i].length <= 100`
• `2 <= target.length <= 100`
• `nums[i]` and `target` consist of digits.
• `nums[i]` and `target` do not have leading zeros.