What is the time complexity of the Dynamic Programming approach for solving the Word Break problem?

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What is the time complexity of the Dynamic Programming approach for solving the Word Break problem?

The time complexity of the Dynamic Programming approach for solving the Word Break problem is O(n^2), where n is the length of the input string.

In the Word Break problem, we are given a string and a dictionary of words. The task is to determine if the string can be segmented into a space-separated sequence of dictionary words.

The Dynamic Programming approach for this problem involves breaking down the problem into smaller subproblems and solving them iteratively. We create a boolean array dp of size n+1, where dp[i] represents whether the substring from index 0 to i-1 can be segmented into dictionary words.

To fill the dp array, we iterate through each index i from 1 to n and check if the substring from index 0 to i-1 can be segmented. We do this by iterating through each index j from 0 to i-1 and checking if dp[j] is true (indicating that the substring from index 0 to j-1 can be segmented) and the substring from index j to i-1 is present in the dictionary. If both conditions are satisfied, we set dp[i] to true.

The time complexity of this approach is determined by the nested loops used to fill the dp array. The outer loop iterates through each index i from 1 to n, and the inner loop iterates through each index j from 0 to i-1. Therefore, the total number of iterations is approximately n^2, resulting in a time complexity of O(n^2).

In conclusion, the time complexity of the Dynamic Programming approach for solving the Word Break problem is O(n^2).