C++函数参考.docVIP

C++函数大全参考 數學函數,所在函數庫為math.h、stdlib.h、string.h、float.h double frexp(double value,int *eptr) 返回value=x*2n中x的值,n存貯在eptr中double ldexp(double value,int exp); 返回value*2exp的值double log(double x) 返回logex的值double log10(double x) 返回log10x的值double pow(double x,double y) 返回xy的值double pow10(int p) 返回10p的值double sqrt(double x) 返回+√x的值double acos(double x) 返回x的反餘弦cos-1(x)值,x為弧度double asin(double x) 返回x的反正弦sin-1(x)值,x為弧度double atan(double x) 返回x的反正切tan-1(x)值,x為弧度double atan2(double y,double x) 返回y/x的反正切tan-1(x)值,y的x為弧度double cos(double x) 返回x的餘弦cos(x)值,x為弧度double sin(double x) 返回x的正弦sin(x)值,x為弧度double tan(double x) 返回x的正切tan(x)值,x為弧度double cosh(double x) 返回x的雙曲餘弦cosh(x)值,x為弧度double sinh(double x) 返回x的雙曲正弦sinh(x)值,x為弧度double tanh(double x) 返回x的雙曲正切tanh(x)值,x為弧度double hypot(double x,double y) 返回直角三角形斜邊的長度(z),x和y為直角邊的長度,z2=x2+y2double ceil(double x) 返回不小於x的最小整數double floor(double x) 返回不大於x的最大整數void srand(unsigned seed) 初始化隨機數發生器int rand() 產生一個隨機數並返回這個數double poly(double x,int n,double c[])從參數產生一個多項式double modf(double value,double *iptr)將雙精度數value分解成尾數和階double fmod(double x,double y) 返回x/y的餘數double frexp(double value,int *eptr) 將雙精度數value分成尾數和階double atof(char *nptr) 將字符串nptr轉換成浮點數並返回這個浮點數double atoi(char *nptr) 將字符串nptr轉換成整數並返回這個整數double atol(char *nptr) 將字符串nptr轉換成長整數並返回這個整數char *ecvt(double value,int ndigit,int *decpt,int *sign)將浮點數value轉換成字符串並返回該字符串char *fcvt(double value,int ndigit,int *decpt,int *sign)將浮點數value轉換成字符串並返回該字符串char *gcvt(double value,int ndigit,char *buf)將數value轉換成字符串並存於buf中,並返回buf的指針char *ultoa(unsigned long value,char *string,int radix)將無符號整型數value轉換成字符串並返回該字符串,radix為轉換時所用基數char *ltoa(long value,char *string,int radix)將長整型數value轉換成字符串並返回該字符串,radix為轉換時所用基數char *itoa(int value,char *string,int radix)將整數value轉換成字符串存入string,radix為轉換時所用基數double atof(char *nptr) 將字符串nptr轉換成雙精度數,並返回這個數,錯誤返回0int atoi(char *nptr) 將字符串nptr轉換成整型數, 並返回這個數,錯誤返回0long atol(char *nptr) 將字符串nptr轉換成長整型數,並返回這個數,錯誤返回0double strtod(char *str,char **endptr)將