算法

- (void)viewDidLoad {
    [super viewDidLoad];
    int array[] = {1,2,12,31,43,11,2,3,76,23,98};
    int count = sizeof(array) / sizeof(array[1]);
//    bubbleFunc(array, count);
//    selectedFunc(array,count);
//    insertFunc(array,count);
    shellSort(array,count);
    for (int i=0; i<count; i++) {
        NSLog(@"%ld",array[i]);
    }
}


- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

void bubbleFunc(int* array, int count) {
    int i,j,temp;
    for (i=0; i<count-1; i++) {
        for (j=0; j<count-1-i;j++) {
            if (array[j]<array[j+1]) {
                temp = array[j];
                array[j] = array[j+1];
                array[j+1] = temp;
            }
        }
    }
}

void selectedFunc (int *array, int count) {
    
    int i,j,maxIndex,temp;
    for (i=0;i<count-1;i++) {
        maxIndex = i;
        for (j=i+1;j<count;j++) {
            if (array[maxIndex]<array[j]) {
                maxIndex = j;
            }
        }
        temp = array[maxIndex];
        array[maxIndex] = array[i];
        array[i] = temp;
    }
}

void insertFunc (int *array, int count) {
    int i,j,temp;
    
    for (i=1;i<count;i++) {
        if (array[i] < array[i-1]) {
            temp = array[i];
            for (j=i-1;j>=0 && array[j]>temp;j--) {
                array[j+1] = array[j];
            }
            array[j+1] = temp;
        }
    }
}


void  shellSort(int *array, int count) {
    //希尔排序可以理解为将一个大数组按照间隔inc分为inc个小数组
    //每个数组按照直接插入排序进行处理
    int inc =count;
    int i,j,tmp = 0;
    do{
        inc = inc/4 + 1;
        
        for(i=inc;i<count;i++){
            if(array[i] < array[i-inc]){
                tmp = array[i];

                for(j=i-inc;j>=0 && tmp < array[j]; j-=inc){
                    array[j+inc] = array[j];
                }
                
                array[j+inc] = tmp;
            }
        }
    }
    while(inc>1);
}
@end