几个小函数

生成随机数：
int random(double start, double end){ return (int)(start+(end-start)*rand()/(RAND_MAX + 1.0));}

生成随即字符串：

#define STR_NUM 2000000//生成字符串的个数#define MIN_STR_LEN 10#define MAX_STR_LEN 20vector<string> vec;void RndString(){vec.reserve(STR_NUM);string str = "";char* szChar = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";int strLength = random(MIN_STR_LEN, MAX_STR_LEN);int randCharPos;int len = strlen(szChar);int i = 0, j = 0;//生成随机字符串for (i=0;i<STR_NUM;i++){for (j=0;j<strLength;j++){randCharPos = random(0, len);str += szChar[randCharPos];}vec.push_back(str);strLength = random(MIN_STR_LEN, MAX_STR_LEN);str = "";}}