leetcode-剑指59-I-OK

同主站239,但是239用这段代码会超时,需要优化
address

/**
 * Note: The returned array must be malloced, assume caller calls free().
 */
int* maxSlidingWindow(int* nums, int numsSize, int k, int* returnSize){
    if(numsSize==0){
        returnSize[0] =0;
        return NULL;
    }
    int i,j;    // 循环用的
    returnSize[0] = numsSize-k+1;   // 返回大小
    int* answer = (int*)malloc(sizeof(int)*(numsSize-k+1)); // 需要返回的数
    int count = returnSize[0];
    bool ok[numsSize-k+1];
    for(i = 0; i < count;i++)
        ok[i] = false;
    int order[numsSize+1];
    int mid[numsSize+1];
    for(i = 0;i<numsSize;i++){
        mid[i+1] = nums[i];
        order[i+1] = i;
    }
// 堆调整以及建堆的函数
    void head_adjust(int arr[], int k, int size_adjust){
        arr[0] = arr[k];
        order[0] =order[k];
        int i;
        for (i=2*k ; i <= size_adjust ; i*=2){
            if (i+1<= size_adjust && arr[i] <arr[i+1])
                i +=1;
            if (arr[0]>= arr[i])
                break;
            else{
                arr[k] = arr[i];
                order[k] = order[i];
                k = i;
            }
        }
        arr[k] = arr[0];
        order[k] = order[0];
    }

    void build_max_heap(int *arr, int size){
        for (int i= size/2; i>0; i--){
            head_adjust(arr, i, size);
        }
    }
// 装入函数
    void fill(int position,int big){
        answer[position] = big;
        ok[position] = true;
        count--;
    }
    bool checkfull(){
        if(count==0)
            return true;
        return false;
    }
// 检查 是否在0 ~ numsSize-k中
    bool check(int a){
        if((a>=0)&&(a<=numsSize-k)&&(!ok[a]))
            return true;
        return false;
    }
    void doAbigONE(){
        for(int m = order[1]+1-k; m<=order[1]; m++){
            if(check(m)){
                fill(m,mid[1]);
                if(checkfull())
                    return;
            }
        }
    }
// 每次对大根堆的根进行处理,然后把尾 换到根来,调整根,循环往复,直到滑动窗口被填完
    build_max_heap(mid,numsSize);
    doAbigONE();
    for(i = numsSize; i>1; i--){
        if(checkfull())
            break;
        mid[1] = mid[i];
        order[1] = order[i];
        head_adjust(mid,1,i-1);
        doAbigONE();
    }
    return answer;
}
原文地址:https://www.cnblogs.com/gallien/p/14322883.html