15个梨分给5个人的组合算法

- (NSArray *)createRandomArrayForCount:(NSInteger)aCount min:(NSInteger)aMin max:(NSInteger)aMax people:(NSInteger)aPeople

{

    if (aMin > aCount * 1.0f / aPeople) return nil;

    

    int m = 0;

    NSArray *array = nil;

    while (YES)

    {

        NSMutableArray *resultArray = [NSMutableArray array];

        

        //返回一个组合数组：把count个梨分给people个人，每人最少min，最多max个

        NSInteger count = aCount;

        NSInteger min = aMin;

        NSInteger max = aMax;

        NSInteger people = aPeople;

        

        NSInteger beLeft = (count - people * (min - 1)) - 1;

        

        NSMutableArray *randomArray = [NSMutableArray array];

        for (int i = 0; i < beLeft; i++)

        {

            [randomArray addObject:@(i)];

        }

        

        NSInteger pre = 0;

        for (int i = 0; i < people - 1; i++)

        {

            int randomIndex = arc4random() % randomArray.count;

            NSNumber *num = randomArray[randomIndex];

            [resultArray addObject:num];