算法

/*

  • 冒泡排序,相邻两个对比,前者比后者大,交换位置

*/

pragma mark - 冒泡降序排序

  • (void)bubbleDescendingOrderSortWithArray:(NSMutableArray *)descendingArr
    {
    for (int i = 0; i < descendingArr.count; i++) {
    for (int j = 0; j < descendingArr.count - 1 - i; j++) {
    if ([descendingArr[j] intValue] < [descendingArr[j + 1] intValue]) {
    int tmp = [descendingArr[j] intValue];
    descendingArr[j] = descendingArr[j + 1];
    descendingArr[j + 1] = [NSNumber numberWithInt:tmp];
    }
    }
    }
    NSLog(@"冒泡降序排序后结果:%@", descendingArr);
    }

、、、、、、、、、、、

/*

  • 选择排序,标记最小值,循环比较,替换最小值

*/

pragma mark - 选择升序排序

  • (void)selectionAscendingOrderSortWithArray:(NSMutableArray *)ascendingArr
    {
    for (int i = 0; i < ascendingArr.count; i ++) {
    for (int j = i + 1; j < ascendingArr.count; j ++) {
    if ([ascendingArr[i] integerValue] > [ascendingArr[j] integerValue]) {
    int temp = [ascendingArr[i] intValue];
    ascendingArr[i] = ascendingArr[j];
    ascendingArr[j] = [NSNumber numberWithInt:temp];
    }
    }
    }
    NSLog(@"选择升序排序后结果:%@", ascendingArr);
    }
    、、、、、、、、、、、、、、、、

/*

  • 插入排序,逐个元素拿出来,与其左边元素逐个对比,碰到比该元素小的元素,则插入在对比元素后

*/

pragma mark - 插入升序排序

  • (void)insertionAscendingOrderSort:(NSMutableArray *)ascendingArr
    {
    for (NSInteger i = 1; i < ascendingArr.count; i ++) {
    NSInteger temp = [ascendingArr[i] integerValue];
    for (NSInteger j = i - 1; j >= 0 && temp < [ascendingArr[j] integerValue]; j --) {
    ascendingArr[j + 1] = ascendingArr[j];
    ascendingArr[j] = [NSNumber numberWithInteger:temp];
    }
    }
    NSLog(@"插入升序排序结果:%@",ascendingArr);
    }

、、、、、、、、、、、、、、、、

#pragma mark - 快速升序排序

  • (void)quickAscendingOrderSort:(NSMutableArray *)arr leftIndex:(NSInteger)left rightIndex:(NSInteger)right
    { if (left < right) {
    NSInteger temp = [self getMiddleIndex:arr leftIndex:left rightIndex:right];
    [self quickAscendingOrderSort:arr leftIndex:left rightIndex:temp - 1];
    [self quickAscendingOrderSort:arr leftIndex:temp + 1 rightIndex:right];
    }
    NSLog(@"快速升序排序结果:%@", arr);
    }
  • (NSInteger)getMiddleIndex:(NSMutableArray *)arr leftIndex:(NSInteger)left rightIndex:(NSInteger)right
    {
    NSInteger tempValue = [arr[left] integerValue]; while (left < right) { while (left < right && tempValue <= [arr[right] integerValue]) {
    right --;
    } if (left < right) {
    arr[left] = arr[right];
    } while (left < right && [arr[left] integerValue] <= tempValue) {
    left ++;
    } if (left < right) {
    arr[right] = arr[left];
    }
    }
    arr[left] = [NSNumber numberWithInteger:tempValue]; return left;
    }

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