数组大小不正确

本文介绍了数组大小不正确的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 #include <stdio.h> void Heapify(int num[], int start, int end) { int root = start; while(root*2+1<=end) { // at least one child exists int swap = root; int lchild = root*2+1; int rchild = root*2+2; if(num[swap]<num[lchild]){ swap = lchild; } if(rchild<=end && num[swap]<num[rchild]){ swap = rchild; } if(swap!=root){ // swap here int temp = num[root]; num[root] = num[swap]; num[swap] = temp; root = swap; } else return; } } void buildHeap(int num[]) { int length=sizeof(num)/sizeof(num[0]); int start = (length/2)-1; // Starting from last parent int end = length-1; while(start>=0){ Heapify(num,start, end); if(start==0) break; start= start-1; } } void heapsort(int num[]) { int length=sizeof(num)/sizeof(num[0]); printf("length = %d ", length); // length = 1 (Wrong) buildHeap(num); int i; //for (i = 0; i < length; i++) //printf("%d ",num[i]); int end = length-1; while(end>0){ // swap first elem with last int temp = num[0]; num[0] = num[end]; num[end] = temp; Heapify(num,0,end-1); end--; } } int main() { int num[]={1,7,-32,4,101,-99,16,3}; heapsort(num); return 0; }

codepad/zcfNOtye

当我在main中打印它时，长度显示正确但在函数内部（堆排序），则显示错误。我在传递数组时找不到任何错误。我缺少什么？

When I print it in main, the length is showing correct but inside the function(heap sort), its showing wrong. I can't find any mistakes in passing the array. What am I missing?

推荐答案

数组作为参数传递给指针时会衰减，您需要将数组的长度作为

Arrays decay to pointers when passed as parameters, you need to pass the length of the array as a separate parameter.

即：找不到这样的数组长度。

I.e.: you can't find the length of the array like this.

void buildHeap(int num[]) { int length=sizeof(num)/sizeof(num[0]); }

sizeof（num）将返回 sizeof（int *）。