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Defined in header <stdlib.h> | ||
div_t div(int x,int y); | (1) | |
ldiv_t ldiv(long x,long y); | (2) | |
lldiv_t lldiv(longlong x,longlong y); | (3) | (since C99) |
Defined in header <inttypes.h> | ||
| (4) | (since C99) | |
Computes both the quotient and the remainder of the division of the numeratorx by the denominatory.
Computes quotient and remainder simultaneously. The quotient is the algebraic quotient with any fractional part discarded (truncated towards zero). The remainder is such thatquot* y+ rem== x. | (until C99) |
Computes the quotient (the result of the expressionx/ y) and remainder (the result of the expressionx% y) simultaneously. | (since C99) |
Contents |
| x, y | - | integer values |
If both the remainder and the quotient can be represented as objects of the corresponding type (int,long,longlong,intmax_t, respectively), returns both as an object of typediv_t,ldiv_t,lldiv_t,imaxdiv_t defined as follows:
struct div_t{int quot;int rem;};
or
struct div_t{int rem;int quot;};
struct ldiv_t{long quot;long rem;};
or
struct ldiv_t{long rem;long quot;};
struct lldiv_t{longlong quot;longlong rem;};
or
struct lldiv_t{longlong rem;longlong quot;};
or
If either the remainder or the quotient cannot be represented, the behavior is undefined.
Until C99, the rounding direction of the quotient and the sign of the remainder in the built-in division and remainder operators was implementation-defined if either of the operands was negative, but it was well-defined indiv andldiv.
On many platforms, a single CPU instruction obtains both the quotient and the remainder, and this function may leverage that, although compilers are generally able to merge nearby/ and% where suitable.
#include <assert.h>#include <limits.h>#include <math.h>#include <stdio.h>#include <stdlib.h> void reverse(char* first,char* last){for(--last; first< last;++first,--last){char c=*last;*last=*first;*first= c;}} // returns empty buffer in case of buffer overflowchar* itoa(int n,int base,char* buf,size_t buf_size){assert(2<= base&& base<=16&& buf&& buf_size); div_t dv={.quot= n};char* p= buf;do{if(!--buf_size)return(*buf='\0'), buf; dv= div(dv.quot, base);*p++="0123456789abcdef"[abs(dv.rem)];}while(dv.quot);if(n<0)*p++='-';*p='\0'; reverse(buf, p);return buf;} int main(void){char buf[16];printf("%s\n", itoa(0,2, buf,sizeof buf));printf("%s\n", itoa(007,3, buf,sizeof buf));printf("%s\n", itoa(12346,10, buf,sizeof buf));printf("%s\n", itoa(-12346,10, buf,sizeof buf));printf("%s\n", itoa(-42,2, buf,sizeof buf));printf("%s\n", itoa(INT_MAX,16, buf,sizeof buf));printf("%s\n", itoa(INT_MIN,16, buf,sizeof buf));}
Possible output:
02112346-12346-1010107fffffff-80000000
(C99)(C99) | computes remainder of the floating-point division operation (function)[edit] |
(C99)(C99)(C99) | computes signed remainder of the floating-point division operation (function)[edit] |
(C99)(C99)(C99) | computes signed remainder as well as the three last bits of the division operation (function)[edit] |
C++ documentation fordiv | |
| 1. | Euclidean division — From Wikipedia. |
| 2. | Modulo (and Truncated division) — From Wikipedia. |
