如何生成数值向量中2、3、4个元素组合的所有求和结果列表（R语言骰子向量示例）

Hey there! Let's walk through how to generate the list you need—including every element from your dice vector plus all possible sums of 2, 3, or 4 elements combined.

First, let's recap your setup: you've got a target value target.mountain <- 10 and generate your dice vector with Roll_dice <- sample(1:6, 4, replace=TRUE). For example, let's use your sample vector c(6,5,3,2) to demonstrate.

Step-by-Step Code #

Here's a clean, straightforward way to get all the required sums in R:

# Your existing setup
target.mountain <- 10
Roll_dice <- sample(1:6, 4, replace = TRUE)
# Example vector (uncomment to test with your sample)
# Roll_dice <- c(6,5,3,2)

# Initialize a list to store sums for each combination size
all_combo_sums <- list()

# Loop through combination sizes 1 to 4
for (k in 1:4) {
  # Generate all unique combinations of k elements from Roll_dice
  combinations <- combn(Roll_dice, k)
  # Calculate the sum for each combination
  sum_per_combo <- colSums(combinations)
  # Add these sums to our list
  all_combo_sums[[k]] <- sum_per_combo
}

# Convert the list to a single vector (unsorted)
unsorted_result <- unlist(all_combo_sums)

# Optional: Sort the result to match your example's structure
sorted_result <- sort(unsorted_result)

# Print the sorted result
print(sorted_result)

Example Output #

Using your sample Roll_dice <- c(6,5,3,2), the sorted_result will look like this:

[1]  2  3  5  5  6  7  8  8  9 10 11 11 13 14 16

How It Works #

• combn(Roll_dice, k) generates every possible subset of k elements from your dice vector. For k=1, this is just each individual element.
• colSums(combinations) calculates the sum for each subset (since combn returns subsets as columns).
• We collect all these sums in a list, then unlist to get a flat vector. Sorting it gives the organized output you showed in your example.

If you don't need the sorted version, just use unsorted_result instead—it will include all values in the order of combination sizes (individual elements first, then 2-element sums, etc.).

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