Maximum Length of Pair Chain LeetCode solution in C++

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class Solution {
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 public:
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  int findLongestChain(vector<vector<int>> &arr) {
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    if (arr.size() == 1) {
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      return 1;
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    }
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    vector<pair<int, int>> v;
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    for (int i = 0; i < arr.size(); i++) {
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      v.push_back({arr[i][0], arr[i][1]});
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    }
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    sort(v.begin(), v.end());
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    vector<int> dp(v.size(), 0);
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    int ans = INT_MIN;
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    dp[0] = 1;
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    for (int i = 1; i < v.size(); i++) {
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      int temp = 0;
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      for (int j = i - 1; j >= 0; j--) {
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        if (v[j].second < v[i].first) {
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          temp = max(temp, dp[j]);
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        }
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      }
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      dp[i] = 1 + temp;
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      ans = max(ans, dp[i]);
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    }
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    return ans;
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  }
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};