C常用函数实现

Posted on | In

Softmax

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
//查找最大元素
float max_element(float* src, int count){
    float max = src[0];
    for (size_t i = 0; i < count; i++)
    {
        if(src[i] > max)
            max = src[i];    
    }
    return max;
}

//对一行进行softmax
void softmax(float *src, float *dst, int count)
{
    float max = max_element(src, count);
    float denominator = 0.;
    for (size_t i = 0; i < count; i++)
    {
        dst[i] = std::exp(src[i] - max);
        denominator += dst[i];
    }
    for (size_t i = 0; i < count; i++)
    {
        dst[i] /= denominator;
    }
}

去除空格

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
void deleteAllMark(string &s, const string &mark)
{
    size_t nSize = mark.size();
    while(1)
    {
        size_t pos = s.find(mark);    //  尤其是这里
        if(pos == string::npos)
        {
            return;
        }
        
        s.erase(pos, nSize);
    }
}


char *Trim(char *str)
{
    unsigned int uLen = strlen(str);
    
    if(0 == uLen)
    {
        return str;
    }
    
    char *strRet = (char *)malloc(uLen + 1);
    memset(strRet, 0, uLen+1);
    
    unsigned int i = 0, j = 0;
    for(i=0; i<uLen+1; i++)
    {
        if(str[i] != ' ')
        {
            strRet[j++] = str[i];
        }
    }
    strRet[j] = '\0';
    
    return strRet;
}

切片

1
2