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"Find Median from Data Stream": dynamic resize for heap

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src
- 295.c

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+27

-16

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`‎src/295.c`

Lines changed: 27 additions & 16 deletions

Original file line number	Diff line number	Diff line change
`@@ -1,11 +1,11 @@`
`1`	`1`	`#include <stdio.h>`
`2`	`2`	`#include <stdlib.h>`
`3`	`3`
`4`		`-static const int MAXN = 102400;`
`5`		`-`
`6`	`4`	`struct MedianFinder {`
`7`	`5`	`int maxHeap; / store the smaller half */`
`8`	`6`	`int minHeap; / store the larger half */`
	`7`	`+ int maxHeapCapacity;`
	`8`	`+ int minHeapCapacity;`
`9`	`9`	`int maxHeapSize;`
`10`	`10`	`int minHeapSize;`
`11`	`11`	`double medium;`
`@@ -17,11 +17,20 @@ void swap(int a, int b) {`
`17`	`17`	`*b = c;`
`18`	`18`	`}`
`19`	`19`
`20`		`-void addheap(int heap, int size, int data) {`
`21`		`- if (*size < MAXN - 1) {`
`22`		`- heap[*size] = data;`
`23`		`- (*size)++;`
	`20`	`+void addHeap(int *heap, int size, int *capacity, int data) {`
	`21`	`+ if (size == capacity) {`
	`22`	`+ int new_capacity = (capacity) 2; /* resize */`
	`23`	`+ int newHeap = (int )malloc(new_capacity * sizeof(int));`
	`24`	`+ for (int i = 0; i < *capacity; i++) {`
	`25`	`+ newHeap[i] = (*heap)[i];`
	`26`	`+ }`
	`27`	`+ if (*heap)`
	`28`	`+ free(*heap);`
	`29`	`+ *heap = newHeap;`
	`30`	`+ *capacity = new_capacity;`
`24`	`31`	`}`
	`32`	`+ (heap)[size] = data;`
	`33`	`+ (*size)++;`
`25`	`34`	`}`
`26`	`35`
`27`	`36`	`void siftUpMax(int *heap, int size) {`
`@@ -77,9 +86,11 @@ void siftDownMin(int *heap, int size) {`
`77`	`86`	`/** Initialize your data structure here. */`
`78`	`87`	`struct MedianFinder* MedianFinderCreate() {`
`79`	`88`	`struct MedianFinder mf = (struct MedianFinder )malloc(sizeof(struct MedianFinder));`
`80`		`- mf->maxHeap = (int )malloc(MAXN sizeof(int));`
`81`		`- mf->minHeap = (int )malloc(MAXN sizeof(int));`
	`89`	`+ mf->maxHeap = (int *)malloc(sizeof(int));`
	`90`	`+ mf->minHeap = (int *)malloc(sizeof(int));`
	`91`	`+ mf->maxHeap[0] = mf->minHeap[0] = 0;`
`82`	`92`	`mf->minHeapSize = mf->maxHeapSize = 0;`
	`93`	`+ mf->minHeapCapacity = mf->maxHeapCapacity = 1;`
`83`	`94`	`mf->medium = 0;`
`84`	`95`	`return mf;`
`85`	`96`	`}`
`@@ -90,33 +101,33 @@ void addNum(struct MedianFinder* mf, int num) {`
`90`	`101`
`91`	`102`	`if (mf->maxHeapSize == mf->minHeapSize) {`
`92`	`103`	`if (num > mf->medium) {`
`93`		`- addheap(mf->minHeap, &mf->minHeapSize, num);`
	`104`	`+ addHeap(&mf->minHeap, &mf->minHeapSize, &mf->minHeapCapacity, num);`
`94`	`105`	`siftUpMin(mf->minHeap, mf->minHeapSize);`
`95`	`106`	`mf->medium = mf->minHeap[0];`
`96`	`107`	`}`
`97`	`108`	`else {`
`98`		`- addheap(mf->maxHeap, &mf->maxHeapSize, num);`
	`109`	`+ addHeap(&mf->maxHeap, &mf->maxHeapSize, &mf->maxHeapCapacity, num);`
`99`	`110`	`siftUpMax(mf->maxHeap, mf->maxHeapSize);`
`100`	`111`	`mf->medium = mf->maxHeap[0];`
`101`	`112`	`}`
`102`	`113`	`}`
`103`	`114`	`else {`
`104`	`115`	`if (num > mf->minHeap[0]) {`
`105`		`- addheap(mf->minHeap, &mf->minHeapSize, num);`
	`116`	`+ addHeap(&mf->minHeap, &mf->minHeapSize, &mf->minHeapCapacity, num);`
`106`	`117`	`siftUpMin(mf->minHeap, mf->minHeapSize);`
`107`	`118`	`if (mf->minHeapSize >= mf->maxHeapSize + 2) {`
`108`		`- addheap(mf->maxHeap, &mf->maxHeapSize, mf->minHeap[0]);`
	`119`	`+ addHeap(&mf->maxHeap, &mf->maxHeapSize, &mf->maxHeapCapacity, mf->minHeap[0]);`
`109`	`120`	`siftUpMax(mf->maxHeap, mf->maxHeapSize);`
`110`	`121`	`swap(&mf->minHeap[0], &mf->minHeap[mf->minHeapSize - 1]);`
`111`	`122`	`mf->minHeapSize--;`
`112`	`123`	`siftDownMin(mf->minHeap, mf->minHeapSize);`
`113`	`124`	`}`
`114`	`125`	`}`
`115`	`126`	`else {`
`116`		`- addheap(mf->maxHeap, &mf->maxHeapSize, num);`
	`127`	`+ addHeap(&mf->maxHeap, &mf->maxHeapSize, &mf->maxHeapCapacity, num);`
`117`	`128`	`siftUpMax(mf->maxHeap, mf->maxHeapSize);`
`118`	`129`	`if (mf->maxHeapSize >= mf->minHeapSize + 2) {`
`119`		`- addheap(mf->minHeap, &mf->minHeapSize, mf->maxHeap[0]);`
	`130`	`+ addHeap(&mf->minHeap, &mf->minHeapSize, &mf->minHeapCapacity, mf->maxHeap[0]);`
`120`	`131`	`siftUpMin(mf->minHeap, mf->minHeapSize);`
`121`	`132`	`swap(&mf->maxHeap[0], &mf->maxHeap[mf->maxHeapSize - 1]);`
`122`	`133`	`mf->maxHeapSize--;`
`@@ -136,8 +147,8 @@ double findMedian(struct MedianFinder* mf) {`
`136`	`147`	`/** Deallocates memory previously allocated for the data structure. */`
`137`	`148`	`void MedianFinderFree(struct MedianFinder* mf) {`
`138`	`149`	`if (mf == NULL) return;`
`139`		`- free(mf->maxHeap);`
`140`		`- free(mf->minHeap);`
	`150`	`+ if (mf->maxHeap) free(mf->maxHeap);`
	`151`	`+ if (mf->minHeap) free(mf->minHeap);`
`141`	`152`	`free(mf);`
`142`	`153`	`}`
`143`	`154`

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`‎src/295.c`

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