供参考！！！！ //产生随机数（浮点数），位于区间[a,b]或者[b,a] double randDbl(double a,double b) { return a+static_cast<double>(rand())/RAND_MAX*(b-a); }

//产生随机数（整数），位于区间[a,b]或者[b,a] int randInt(int a, int b) { if(a<b) return a + rand()%(b-a+1); else if(a>b) return b + rand()%(a-b+1); else // a==b return a; }

int main(int argc, char *argv[]) { int a=1, b=6; double c=1.0, d=6.0;

srand(time(0)); //保证每次运行产生的随机数都不一样 //测试随机数的产生是否正确 for(int i=0; i<10000; ++i) { if( randInt(a,b)<a || randInt(a,b) >b) cout << "randInt(" << a << "," << b << ") is ERROR\n"; if( randDbl(c,d)<c || randDbl(c,d) >d) cout << "randDbl(" << c << "," << d << ") is ERROR\n"; } return 0; }