Implementation of Heap Sort

#include<stdio.h>

#define LEFT(i) 2*i+1
#define RIGHT(i) 2*i+2

void maxHeapify(int a[],int p,int len){
int max = p;
int temp;
if(LEFT(p) < len && a[LEFT(p)] > a[p]){
max = LEFT(p);
}
if(RIGHT(p) < len && a[RIGHT(p)] > a[max]){
max = RIGHT(p);
}
if(max != p){
temp = a[max];
a[max] = a[p];
a[p] = temp;
maxHeapify(a,max,len);
}
}

void buildHeap(int a[],int len){
int i;
for(i=(len-2)/2;i>=0;i--){
maxHeapify(a,i,len);
}
}

void heapSort(int a[],int len){
buildHeap(a,len);
int i,temp;
int heapLen = len;
for(i=0;i<len;i++){
temp = a[0];
a[0] = a[heapLen-1];
a[heapLen-1] = temp;
heapLen--;
maxHeapify(a,0,heapLen);
}
}

void printSorted(int a[],int len){
int i;
for(i=0;i<len;i++){
printf("%d\t",a[i]);
}
}

int main(){
int a[] = {9,8,7,6,5,4,3,2,1};
int len = sizeof(a)/sizeof(a[0]);
heapSort(a,len);
printSorted(a,len);
return 0;
}

Sorted array is rotated. Find starting point or the index of the minimum element

// INPUT : {7,0,1,2,3,4,5,6}
// OUTPUT : array starts at value=0 and index=1

#include<stdio.h>

int findstartRecur(int a[],int start,int end){
int mid = (start+end)/2;
if(a[start] < a[end]){
return start;
}
if(end-start < 2){
return (a[end] < a[start])?end:start;
}
if(a[mid] > a[start]){
return findstartRecur(a,mid+1,end);
} else{
return findstartRecur(a,start,mid);
}
}

int main(){
int a[] = {7,0,1,2,3,4,5,6};
int start = findstartRecur(a,0,sizeof(a)/sizeof(int)-1);
printf("array starts at value=%d and index=%d",a[start],start);
return 0;
}

Merge 2 Sorted Arrays (without using extra array)

// INPUT : int A[5] = {1,2,5,7,10};
// int B[12] = {0,3,4,6,8,9,13};
// OUTPUT : {0,1,2,3,4,5,6,7,8,9,10,13}

#include<stdio.h>

void mergeArray(int *A,int *B,int m,int n){
//A has m elements, B has n-m elements
int i=m-1,j=n-m-1,k=n-1;
while(i>=0 && j>=0){
if(A[i] > B[j]){
B[k--] = A[i--];
} else {
B[k--] = B[j--];
}
}
if(j<0){
while(i>=0){
B[k--] = A[i--];
}
}
}

int main(){
int A[5] = {1,2,5,7,10};
int B[12] = {0,3,4,6,8,9,13};
int sizeA = sizeof(A)/sizeof(int);
int sizeB = sizeof(B)/sizeof(int);
int i;
mergeArray(A,B,sizeA,sizeB);
for(i=0;i<sizeB;i++){
printf("%d ",B[i]);
}
return 0;
}