I sum the number from triangle bottom, so there is no need to check the minimum sum in array. sum[0] is the result.

```
public int minimumTotal(List<List<Integer>> triangle) {
if (triangle == null || triangle.size() == 0) {
return 0;
}
int[] sum = new int[triangle.size() + 1];
for (int i = triangle.size() - 1; i >= 0; i--) {
for (int j = 0; j < triangle.get(i).size(); j++) {
sum[j] = Math.min(sum[j], sum[j + 1]) + triangle.get(i).get(j);
}
}
return sum[0];
}
```