#include #include void main(){ int a = 4, b = -5, c = 3; int max = a; if(abs(b) > abs(max) ) { max = b; } if(abs(c) > abs(max)) { max = c; } printf("max:%d", max);}=====================================abs Calculates the absolute value. int abs( int n ); or Example /* ABS.C: This program computes and displays * the absolute values of several numbers. */ #include #include #include void main( void ) { int ix = -4, iy; long lx = -41567L, ly; double dx = -3.141593, dy; iy = abs( ix ); printf( "The absolute value of %d is %d", ix, iy); ly = labs( lx ); printf( "The absolute value of %ld is %ld", lx, ly); dy = fabs( dx ); printf( "The absolute value of %f is %f", dx, dy ); } Output The absolute value of -4 is 4 The absolute value of -41567 is 41567 The absolute value of -3.141593 is 3.141593。