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);
  }

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/*

• 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);
  }
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/*

• 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);
  }

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#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;
 }