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Nested List Weight Sum

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Question

Given a nested list of integers, return the sum of all integers in the list weighted by their depth.

Each element is either an integer, or a list – whose elements may also be integers or other lists.

Example 1:
Input: [[1,1],2,[1,1]]
Output: 10
Explanation: Four 1’s at depth 2, one 2 at depth 1.

Solution

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/*
DFS
*/
int result = 0;
public int depthSum(List<NestedInteger> nestedList) {
    dfs(nestedList, 1);
    return result;
}
public void dfs(List<NestedInteger> nestedList, int depth){
    for ( int i = 0; i < nestedList.size(); i++){
        NestedInteger temp = nestedList.get(i);
        if ( !temp.isInteger() ){
            dfs(temp.getList(), depth+1);
        }else{
            result += temp.getInteger() * depth;
        }
    }
}