C语言实现竖条转横条：给定高度列表生成横向条形及位置方案求助

Alright, let's figure out how to build this C program. The key here is to shift our focus from vertical bars to horizontal layers—each horizontal bar we need to output represents a continuous stretch of vertical bars that are tall enough to reach a specific height. Let's break this down step by step.

1. 输入处理 #

First, we need to read the input list of numbers (like "1 5 3") and store them in an array. In C, you can do this easily with a loop using scanf, which will keep reading integers until it hits a non-numeric character (like a newline). We'll also keep track of how many numbers we've read (the length of the array).

2. 确定最大高度 #

Next, find the maximum height in the array. This tells us how many horizontal layers we need to process—we'll check every height from 1 up to this maximum value.

3. 遍历每一层高度 #

For each height h from 1 to the maximum height:

• Scan through the vertical bar heights to find all contiguous ranges where the vertical bar's height is at least h.
• To find these ranges:
  • Start at the beginning of the array, skip over any vertical bars that are shorter than h.
  • When you find a bar that's tall enough, mark its index as the start of the range.
  • Keep moving forward until you hit a bar that's too short (or the end of the array)—this index is the end of the range.
  • Output the range in the format [start, end)@h.
  • Repeat until you've scanned the entire array for this height.

伪代码 #

// Step 1: Read input into an array
Initialize an array to hold heights
n = 0
while input has integers left:
    read integer into heights[n]
    n += 1

if n == 0:
    exit (no input to process)

// Step 2: Find maximum height
max_h = heights[0]
for i from 1 to n-1:
    if heights[i] > max_h:
        max_h = heights[i]

// Step 3: Process each height layer
for h from 1 to max_h:
    i = 0
    while i < n:
        // Skip bars too short for current height
        while i < n and heights[i] < h:
            i += 1
        if i >= n:
            break  // No more bars for this height
        
        start = i
        // Find end of the contiguous tall bars
        while i < n and heights[i] >= h:
            i += 1
        
        // Output the formatted string
        print "[%d,%d)@%d" % (start, i, h)

C语言实现细节 #

• Input handling: You can use a fixed-size array (like int heights[100];) for simplicity, or dynamically allocate memory with malloc if you need to handle arbitrary input sizes. Here's a quick snippet for reading input:

  int heights[100];
  int n = 0;
  // Keep reading integers until scanf fails (e.g., newline is entered)
  while (scanf("%d", &heights[n]) == 1) {
      n++;
  }
  

• Finding max height: A straightforward loop will do the trick—initialize max_h to the first element, then iterate through the rest of the array to update it if you find a larger value.
• Output formatting: Use printf with the format string printf("[%d,%d)@%d\n", start, i, h); to get the required output style.
• Edge cases: Don't forget to handle empty input (n=0) by exiting early, or input with all zeros (though the problem example uses positive integers, it's good practice to account for this).

Let's test this logic with your example input "1 5 3":

• Max height is 5, so we process h=1 to 5.
• h=1: All 3 bars are tall enough → output [0,3)@1
• h=2: Bars 1 and 2 are tall enough → output [1,3)@2
• h=3: Bars 1 and 2 are tall enough → output [1,3)@3
• h=4: Only bar 1 is tall enough → output [1,2)@4
• h=5: Only bar 1 is tall enough → output [1,2)@5

Perfect, that matches exactly what you need!

内容的提问来源于stack exchange，提问作者Danielvanheuven