C语言向量左移后右移功能异常，请求错误排查

Hey Giada, I spotted the exact issue causing your right shift to output incorrect results—let's break it down step by step:

The Critical Bug: Unwanted Semicolon #

Look at your right shift loop:

for (i=N-1; i>0; i--); {
    vet[i]=vet[i-1];
}

That semicolon ; right after the for loop declaration is a silent killer! It tells the compiler that the loop has an empty body, so the code block { vet[i]=vet[i-1]; } never runs as part of the loop. Instead, it just executes once (after the loop finishes doing nothing), which completely breaks the shift logic.

The Second (Minor) Check: Correcting the Flow #

Once you remove that semicolon, the loop will work as intended, but let's confirm what it does:

• Starting from the last element (i=N-1) and moving left to the first index (i>0), each element gets replaced by the one before it.
• After the loop finishes, setting vet[0] = 0 correctly puts the zero at the start, turning 2 3 4 0 into 0 2 3 4 as you want.

Corrected Right Shift Code #

Here's the fixed section of your code:

//SHIFT TO THE RIGHT//
// 2 3 4 0 -> 0 2 3 4//
for (i=N-1; i>0; i--) { // Removed the extra semicolon here
    vet[i]=vet[i-1];
}
vet[0]=0;

Test Case Verification #

Let's say you input 4 elements: 1 2 3 4

1. Left shift gives: 2 3 4 0
2. Fixed right shift will output: 0 2 3 4 (exactly what you expected!)

内容的提问来源于stack exchange，提问作者Giada