软件开发岗算法-伪代码_伪代码例题-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_44227650/article/details/145908164

在软件开发岗的笔试中，算法题通常涉及数据处理、逻辑优化、动态规划、图算法等方向。以下是一些常见的算法题类型及其伪代码实现示例：

1. 字符串处理

题目示例：实现字符串反转或判断回文。

FUNCTION reverseString(s: STRING) -> STRING:
    left = 0
    right = length(s) - 1
    WHILE left < right:
        SWAP(s[left], s[right])
        left = left + 1
        right = right - 1
    RETURN s

FUNCTION isPalindrome(s: STRING) -> BOOLEAN:
    reversed = reverseString(s)
    RETURN s == reversed

2. 数组与排序

题目示例：实现快速排序或查找数组中的最大值。

FUNCTION quickSort(arr: ARRAY, low: INT, high: INT):
    IF low < high:
        pivotIndex = partition(arr, low, high)
        quickSort(arr, low, pivotIndex - 1)
        quickSort(arr, pivotIndex + 1, high)

FUNCTION partition(arr: ARRAY, low: INT, high: INT) -> INT:
    pivot = arr[high]
    i = low - 1
    FOR j = low TO high - 1:
        IF arr[j] < pivot:
            i = i + 1
            SWAP(arr[i], arr[j])
    SWAP(arr[i + 1], arr[high])
    RETURN i + 1

3. 动态规划

题目示例：求解最长公共子序列（LCS）。

FUNCTION LCS(s1: STRING, s2: STRING) -> STRING:
    m = length(s1)
    n = length(s2)
    dp = ARRAY[m+1][n+1] INITIALIZED TO 0
    FOR i = 1 TO m:
        FOR j = 1 TO n:
            IF s1[i-1] == s2[j-1]:
                dp[i][j] = dp[i-1][j-1] + 1
            ELSE:
                dp[i][j] = MAX(dp[i-1][j], dp[i][j-1])
    RETURN dp[m][n]

4. 图算法

题目示例：实现Dijkstra算法求解最短路径。

FUNCTION Dijkstra(graph: GRAPH, start: NODE):
    dist = ARRAY[graph.size] INITIALIZED TO INFINITY
    dist[start] = 0
    visited = SET()
    WHILE visited.size < graph.size:
        u = NODE WITH MINIMUM dist[] NOT IN visited
        visited.add(u)
        FOR EACH NEIGHBOR v OF u:
            IF dist[u] + graph[u][v] < dist[v]:
                dist[v] = dist[u] + graph[u][v]
    RETURN dist

5. 数学问题

题目示例：判断一个数是否为质数。

FUNCTION isPrime(n: INT) -> BOOLEAN:
    IF n <= 1:
        RETURN FALSE
    FOR i = 2 TO SQRT(n):
        IF n % i == 0:
            RETURN FALSE
    RETURN TRUE

6. 链表操作

题目示例：反转链表。

FUNCTION reverseList(head: NODE) -> NODE:
    prev = NULL
    curr = head
    WHILE curr != NULL:
        next = curr.next
        curr.next = prev
        prev = curr
        curr = next
    RETURN prev

7. 贪心算法

题目示例：找零钱问题。

FUNCTION coinChange(coins: ARRAY, amount: INT) -> INT:
    coins = SORT(coins, DESCENDING)
    count = 0
    FOR EACH coin IN coins:
        WHILE amount >= coin:
            amount = amount - coin
            count = count + 1
    IF amount == 0:
        RETURN count
    ELSE:
        RETURN -1

8. 递归与回溯

题目示例：求解全排列。

FUNCTION permute(nums: ARRAY) -> ARRAY[ARRAY]:
    result = ARRAY[ARRAY]()
    backtrack(nums, result, 0)
    RETURN result

FUNCTION backtrack(nums: ARRAY, result: ARRAY[ARRAY], start: INT):
    IF start == length(nums):
        result.add(nums.copy())
        RETURN
    FOR i = start TO length(nums) - 1:
        SWAP(nums[start], nums[i])
        backtrack(nums, result, start + 1)
        SWAP(nums[start], nums[i])

9. 滑动窗口

题目示例：求解最长无重复字符子串。

FUNCTION lengthOfLongestSubstring(s: STRING) -> INT:
    charSet = SET()
    left = 0
    maxLen = 0
    FOR right = 0 TO length(s) - 1:
        WHILE s[right] IN charSet:
            charSet.remove(s[left])
            left = left + 1
        charSet.add(s[right])
        maxLen = MAX(maxLen, right - left + 1)
    RETURN maxLen

10. 位运算

题目示例：统计二进制中1的个数。

FUNCTION countBits(n: INT) -> INT:
    count = 0
    WHILE n > 0:
        count = count + (n & 1)
        n = n >> 1
    RETURN count

总结

银行软件开发岗的算法题通常注重逻辑清晰、代码简洁和效率优化。
伪代码的关键是清晰地表达算法思路，避免语法细节。
建议熟悉常见算法模板（如动态规划、回溯、滑动窗口等），并多做练习以提升解题速度。