day05-03-数组乱序

Objective-c

//  day05-03-数组乱序
//
//  Created by Aaron on 15/7/7.
//  Copyright (c) 2015年 Aaron. All rights reserved.
//
#import <Foundation/Foundation.h>
//0 1 2 3 4
//1 2 3 4
#if 0
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        NSArray *array = @[@1,@2,@3,@4,@5,@6,@7,@8];
        NSMutableArray *array1 = [NSMutableArray arrayWithArray:array];
        NSMutableArray *array2 = [NSMutableArray array];
        //控制随机的次数
        for(int i = 0; i < [array count]; i++)
        {
            //根据array1来随下标
            NSInteger index = arc4random_uniform((int)[array1 count]);
            //随出来的对象添加到array2里
            [array2 addObject:array1[index]];
            [array1 removeObjectAtIndex:index];
        }
        NSLog(@"%@",array2);
    }
    return 0;
}
#endif
//1 2 3 4 5
#if 0
int main()
{
    NSMutableArray *array = [NSMutableArray arrayWithArray:@[@1,@2,@3,@4,@5]];
    //控制随机的对象和哪一个元素交换
    for(int i = 0; i < [array count]; i++)
    {
        NSInteger index = arc4random_uniform((int)[array count]-i)+i;
        [array exchangeObjectAtIndex:i withObjectAtIndex:index];
    }
    NSLog(@"%@",array);
}
#endif
#if 0
int main()
{
    NSMutableArray *array = [NSMutableArray arrayWithArray:@[@1,@2,@3,@4,@5]];
    for(int i = 0; i < [array count]-1; i++)
    {
        for(int j = i+1; j < [array count]; j++)
        {
            if(arc4random_uniform(2))
            {
                [array exchangeObjectAtIndex:i withObjectAtIndex:j];
            }
        }
    }
    NSLog(@"%@",array);
}
#endif