Grid Game LeetCode solution in Java

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class Solution {
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  public long gridGame(int[][] grid) {
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    int n = grid[0].length;
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    long preRow1[] = new long[n];
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    long preRow2[] = new long[n];
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    preRow1[0] = grid[0][0];
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    preRow2[0] = grid[1][0];
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    for (int i = 1; i < n; i++) {
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      preRow1[i] += (long) preRow1[i - 1] + (long) grid[0][i];
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      preRow2[i] += (long) preRow2[i - 1] + (long) grid[1][i];
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    }
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    long res = Long.MAX_VALUE;
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    for (int i = 0; i < n; i++) {
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      long top = preRow1[n - 1] - preRow1[i];
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      long bottom = i == 0 ? 0 : preRow2[i - 1];
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      long temp = Math.max(top, bottom);
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      res = Math.min(res, temp);
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    }
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    return res;
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  }
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}