线性查找

//C语言 
int linearSearch(int *arr,int len,int key) {
    if(arr == NULL || len <= 0)
    return -1;
    for(int i = 0;i < len;++i) {
        if(key == arr[i])
        return i;
    }
    return -1;
}

//C++
const size_t arraySize = 100;//数组长度
template<typename T>
size_t linearSearch(const array<T, arraySize> &arr, const T key) {
    int i = 0;
    while (i < arr.size() && arr[i] != key)
        ++i;
    if (i == arr.size())
        return -1;
    else
        return i;
}