Max Protected Population After One-Step Left Relocation

Given an array population of length n (population of each city) and a binary string unit of the same length: unit[i] = '1' means city i currently has one security unit; '0' means none. Relocation rule: for any i > 1, the unit in city i may be moved one step left to city i-1. Each unit can be moved at most once; units in city 1 cannot move further left. If moved, city i loses the unit and city i-1 gains it. A city is protected if it has a unit after all relocations. The protected population is the sum of population[i] over protected cities. Return the maximum protected population achievable by relocating units optimally. Constraints 1 ≤ n ≤ 1e5 1 ≤ population[i] ≤ 1e4 unit consists only of '0' and '1' Example population = [10, 5, 8, 9, 6] unit = "01101" Move the unit at index 2 left to get 10101, then move the unit at index 5 left to get 10110. Protected cities are 1, 3, 4 with sum 10+8+9=27, so output 27. Sample 0 Input: population = [20,10,9,30,20,19], unit = "011011" Output: 80 Sample 1 Input: population = [5,4,5,1], unit = "0111" Output: 14 Example Input 5 10 5 8 9 6 01101 Output 27