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https://github.com/TheAlgorithms/Ruby
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74 lines
1.4 KiB
Ruby
74 lines
1.4 KiB
Ruby
# Find the Highest Altitude
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# There is a biker going on a road trip. The road trip
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# consists of n + 1 points at different altitudes. The
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# biker starts his trip on point 0 with altitude equal 0.
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# You are given an integer array gain of length n where
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# gain[i] is the net gain in altitude between points i
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# and i + 1 for all (0 <= i < n).
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# Return the highest altitude of a point.
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# Example 1:
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#
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# Input: gain = [-5,1,5,0,-7]
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# Output: 1
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# Explanation: The altitudes are [0,-5,-4,1,1,-6].
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# The highest is 1.
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#
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#
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# Approach 1: Creating an additional array
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#
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# @param {Integer[]} gain
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# @return {Integer}
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def largest_altitude(gain)
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arr = [0]
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# calculate altitude array
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(1..gain.count).each do |pointer|
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sum = arr[pointer - 1] + gain[pointer - 1]
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arr.push(sum)
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end
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# find maximum altitude
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max = 0
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arr.each { |i| max = i if max < i }
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max
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end
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gain = [-5, 1, 5, 0, -7]
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largest_altitude(gain)
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# Output: 1
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gain = [-4, -3, -2, -1, 4, 3, 2]
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largest_altitude(gain)
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# Output: 0
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#
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# Approach 2: Without creating an additional array
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#
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# @param {Integer[]} gain
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# @return {Integer}
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def largest_altitude(gain)
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max_alt = alt = 0
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(0...gain.count).each do |i|
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alt += gain[i]
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max_alt = alt if max_alt < alt
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end
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max_alt
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end
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gain = [-5, 1, 5, 0, -7]
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largest_altitude(gain)
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# Output: 1
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gain = [-4, -3, -2, -1, 4, 3, 2]
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largest_altitude(gain)
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# Output: 0
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