1、我们的程序运行过程中每分钟会采集一个整数的数据指标。
持续采集n分钟就得到一个有n个元素的整数数组a[n]。
现在我们需要一个简单的算法,检测采集到的数据指标中,是否有异常。
异常的检测标准是:如果在连续m分钟内的指标的平均值大于w,则说明有异常。
输入:数组a[n], 正整数m, 整数w
返回:有异常返回 1,没有异常返回 0
例如:对于a={1, 5, 1, 3, 2}, m=2, w=2, 返回:1
附加说明:不同的实现方式执行效率不一样,如果能找到一个很高效的算法就更好了。
示例1:
NSArray *firstArray = @[@"1",@"5",@"1",@"3",@"2"];
NSInteger m = 2;
NSInteger w = 2;
[self judgeWithArray:firstArray withTimes:m withValue:w];
- (BOOL)judgeWithArray:(NSArray *)array withTimes:(NSInteger)times withValue:(NSInteger)value
{
__block BOOL isTrue = NO;
NSMutableArray *allTotalNumArray = [[NSMutableArray alloc] initWithCapacity:0];
for (int i = 0; i<array.count; i++) {
if (i>(array.count - times)) {
break;
}
NSInteger totalNum = 0;
[allTotalNumArray addObject:[NSString stringWithFormat:@"%zd",totalNum]];
NSInteger num0 = [array[i] integerValue];
for (int j = 0; j<allTotalNumArray.count; j++) {
NSInteger num1 = [allTotalNumArray[j] integerValue];
if ((i - j)<times) {
num1 += num0;
[allTotalNumArray replaceObjectAtIndex:j withObject:[NSString stringWithFormat:@"%zd",num1]];
}
}
}
[allTotalNumArray enumerateObjectsUsingBlock:^(id _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
CGFloat num2 = [obj floatValue] ;
CGFloat average =ceil(num2/times);
if (average>value) {
isTrue = YES;
*stop = YES;
}
}];
return isTrue;
}
示例2:
[self judgeIsException:@[@1,@2,@2,@3,@1,@5,@3,@2] time:3 standard:3]
- (BOOL)judgeIsException:(NSArray *)arr time:(int)time standard:(int)standard{
int max = time * standard;
int count = (int)arr.count;
int sum = 0;
for (int i = 0; i < count; i++) {
int currentValue = [arr[i] intValue];
if (currentValue <= standard) {
continue;
}else{
int start = i - time + 1;
if (start < 0) {
start = 0;
}
int loop = count - i;
if (loop > time) {
loop = time;
}
while (loop>0) {
sum = 0;
for (int j = start; j < time+start; j++) {
sum += [arr[j] intValue];
}
if (sum>max) {
return YES;
}
start++;
loop--;
}
i = start;
}
}
return NO;
}
2、我们的程序运行过程中用到了一个数组a,数组元素是一个Map/Dictionary。
数组元素的“键”和“值”都是字符串类型。在不同的语言中,对应的类型是:
PHP的array, Java的HashMap, C++的std::map, Objective-C的NSDictionary, Swift的Dictionary, Python的dict, JavaScript的object, 等等
示例:
a[0]["key1"]="value1"
a[0]["key2"]="value2"
a[1]["keyA"]="valueA"
...
为了方便保存和加载,我们使用了一个基于文本的存储结构,数组元素每行一个:
text="key1=value1;key2=value2\nkeyA=valueA\n..."
要求:请实现一个“保存”函数、一个“加载”函数。
text=store(a);
a=load(text);
这两个函数分别用于把数组保存到一个文本字符串中、把文本字符串中的内容读取为数组。
必须自己手写代码实现保存/加载逻辑,严格按照上述的“每行一个、key=value”的格式保存。
附加说明:基于上述格式,如果value中有特殊字符,比如有换行符/分号等怎么办?
如果有思路,请基于上述的格式设计并实现一个完美的方案。
示例:
NSArray *array = @[@{@"key01":@"value\n01",@"key;02":@"value02"},@{@"key11":@"value11",@"key12":@"value12"},@{@"key21":@"value21",@"key22":@"value22"}];
NSLog(@"originArray:%@",array);
NSString *text = [self store:array];
NSLog(@"text:%@",text);
NSArray *loadArray = [self load:text];
NSLog(@"loadArray:%@",[[loadArray description] stringByRemovingPercentEncoding]);
- (NSString *)store:(NSArray <NSDictionary *> *)array
{
NSMutableString *string = [NSMutableString new];
__block BOOL keyBegin = YES;
BOOL nextElement = NO;
for (NSDictionary *dic in array) {
if (nextElement) {
[string appendFormat:@"\n"];
}
keyBegin = YES;
[dic enumerateKeysAndObjectsUsingBlock:^(id _Nonnull key, id _Nonnull obj, BOOL * _Nonnull stop) {
[string appendFormat:@"%@%@=%@",keyBegin?@"":@";",[key stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLPathAllowedCharacterSet]],[obj stringByAddingPercentEncodingWithAllowedCharacters:[NSCharacterSet URLPathAllowedCharacterSet]]];
if (keyBegin) {
keyBegin = NO;
}
}];
nextElement = YES;
}
return string;
}
- (NSArray *)load:(NSString *)text
{
NSMutableArray *array = [NSMutableArray new];
NSArray *tempArray = [text componentsSeparatedByString:@"\n"];
for (NSString *dicString in tempArray) {
NSArray *dicArray = [dicString componentsSeparatedByString:@";"];
NSMutableDictionary *tempDic = [NSMutableDictionary new];
for (NSString *keyValues in dicArray) {
NSArray *dicInfo = [keyValues componentsSeparatedByString:@"="];
[tempDic setObject:dicInfo.lastObject forKey:dicInfo.firstObject];
}
[array addObject:tempDic];
}
return array;
}
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