Minimum Swaps To Make Sequences Increasing LeetCode solution in C++

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class Solution {
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 public:
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  int n;
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  vector<int> nums1, nums2;
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  int dp[200005][3];
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  int find(int index, int sp) {
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    if (index == n) {
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      return 0;
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    }
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    if (dp[index][sp] != -1) {
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      return dp[index][sp];
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    }
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    int prev1 = nums1[index - 1];
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    int prev2 = nums2[index - 1];
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    int ans = 1e8;
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    if (sp) {
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      swap(prev1, prev2);
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    }
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    if (prev1 < nums1[index] && prev2 < nums2[index]) {
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      ans = min(ans, find(index + 1, 0));
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    }
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    if (prev1 < nums2[index] && prev2 < nums1[index]) {
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      ans = min(ans, 1 + find(index + 1, 1));
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    }
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    return dp[index][sp] = ans;
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  }
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  int minSwap(vector<int> &nums1, vector<int> &nums2) {
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    memset(dp, -1, sizeof(dp));
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    nums1.insert(nums1.begin(), -1);
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    nums2.insert(nums2.begin(), -1);
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    n = nums1.size();
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    this->nums1 = nums1;
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    this->nums2 = nums2;
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    return find(1, 0);
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  }
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};