Source

BUBBLE SORT

in this smartcontract you can learn how to use bubble-sort algorithm in solidity.

Problem Description

1. Bubble sort algorithm sort data by comparing two consecutive numbers.
2. The time complexity of this algorithm is O(n^2).

Problem Solution

1. Compare two consecutive number.
2. Switch values if the number with higher index value is smaller.
3. Finalize the result.

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Review

• SmartContract

function _sort(uint[] memory nums) internal pure {
    uint n = nums.length; // save gas
    for (uint i = 0; i < n; ++i) {
        for (uint j = 0; j < n-i-1; ++j) {
            // Comparing consecutive data and switching values if value at j > j+1.
            if (nums[j] > nums[j + 1]) {
                nums[j] = nums[j] + nums[j + 1];
                nums[j + 1] = nums[j] - nums[j + 1];
                nums[j] = nums[j] - nums[j + 1];
            }
        }
        // Value at n-i-1 will be maximum of all the values below this index.
    }
}