复数类型

#include <complex.h>

double complex z = 1.0 + 2.0*I;   /* I 是虚数单位 */

printf("Real: %f, Imag: %f\n", creal(z), cimag(z));
/* Real: 1.0, Imag: 2.0 */

printf("Magnitude: %f\n", cabs(z));   /* sqrt(1^2 + 2^2) = 2.236... */
printf("Phase: %f\n", carg(z));       /* atan2(2, 1) */

#include <complex.h>

double complex a = 1.0 + 2.0*I;
double complex b = 3.0 - 1.0*I;

double complex sum = a + b;         /* 4.0 + 1.0*I */
double complex diff = a - b;        /* -2.0 + 3.0*I */
double complex prod = a * b;        /* (1*3 - 2*(-1)) + (1*(-1) + 2*3)*I = 5.0 + 5.0*I */
double complex quot = a / b;        /* 复数除法 */

#include <complex.h>

double complex z = 1.0 + 1.0*I;

/* 幂和对数 */
double complex z2 = cpow(z, 2);     /* z^2 */
double complex lz = clog(z);        /* ln(z) */
double complex ez = cexp(z);        /* e^z */

/* 三角函数 */
double complex sz = csin(z);
double complex cz = ccos(z);

/* 平方根 */
double complex rz = csqrt(z);

float complex fc;                   /* 单精度复数 */
double complex dc;                  /* 双精度复数 */
long double complex ldc;            /* 扩展精度复数 */

/* 错误：I 未定义 */
double complex z = 1.0 + 2.0*I;

/* 正确 */
#include <complex.h>

double complex z = 1.0 + 2.0*I;
double m = abs(z);                  /* 错误：abs 是整数绝对值 */

/* 正确 */
double m = cabs(z);                 /* 复数绝对值 */