"Self-use" memset for int, long long, float, double extremum how Clear

Link:

#include <stdio.h>int main(){    puts("转载请注明出处[辗转山河弋流歌 by 空灰冰魂]谢谢");    puts("网址：blog.csdn.net/vmurder/article/details/46537613");}

Int

The principle of "more": addition does not explode.
Maximum value: 0x7f
Larger value: 0x3f
Lower value: 0xc0
Minimum value: 0x80

Long Long

The principle of "more": addition does not explode.
Maximum value: 0x7f
Larger value: 0x3f
Lower value: 0xc0
Minimum value: 0x80

Float

"More" principle: to ensure a positioning accuracy.
7f or more until be is-0 (actually a small negative number of >-1.0)
Maximum value: 0x7f
Larger value: 0x4f
Lower value: 0xce
Minimum value: 0xFE
0xFF is -1. #QNAN0000 ... (-∞?) )

Double

"More" principle: to ensure a positioning accuracy.
Maximum value: 0x7f
Larger value: 0x43
Lower value: 0xc2
Minimum value: 0xFE

Experiment Code:

#include <cstdio>#include <cstring>#include <iostream>#include <algorithm>#define N 5using namespace STD;intA[n];Long LongB[n];floatC[n];DoubleD[n];void_int () {puts("");puts("int:");puts("");memsetA0x7f,sizeofa);printf("%d\n", a[0]);memsetA0x80,sizeofa);printf("%d\n", a[0]);memsetA0x81,sizeofa);printf("%d\n", a[0]);puts("");memsetA0XBF,sizeofa);printf("%d%d\n", a[0],a[0]*2);memsetA0xc0,sizeofa);printf("%d%d\n", a[0],a[0]*2);memsetA0xc1,sizeofa);printf("%d%d\n", a[0],a[0]*2);puts("");memsetA0x3e,sizeofa);printf("%d%d\n", a[0],a[0]*2);memsetA0x3f,sizeofa);printf("%d%d\n", a[0],a[0]*2);memsetA0x40,sizeofa);printf("%d%d\n", a[0],a[0]*2);puts("");memsetA0x7e,sizeofa);printf("%d\n", a[0]);memsetA0x7f,sizeofa);printf("%d\n", a[0]);memsetA0x80,sizeofa);printf("%d\n", a[0]);}void_long () {puts("");puts(" Long Long:");puts("");memset(b,0x7f,sizeofb);printf("%i64d\n", b[0]);memset(b,0x80,sizeofb);printf("%i64d\n", b[0]);memset(b,0x81,sizeofb);printf("%i64d\n", b[0]);puts("");memset(b,0XBF,sizeofb);printf("%i64d%i64d\n", b[0],b[0]*2);memset(b,0xc0,sizeofb);printf("%i64d%i64d\n", b[0],b[0]*2);memset(b,0xc1,sizeofb);printf("%i64d%i64d\n", b[0],b[0]*2);puts("");memset(b,0x3e,sizeofb);printf("%i64d%i64d\n", b[0],b[0]*2);memset(b,0x3f,sizeofb);printf("%i64d%i64d\n", b[0],b[0]*2);memset(b,0x40,sizeofb);printf("%i64d%i64d\n", b[0],b[0]*2);puts("");memset(b,0x7e,sizeofb);printf("%i64d\n", b[0]);memset(b,0x7f,sizeofb);printf("%i64d\n", b[0]);memset(b,0x80,sizeofb);printf("%i64d\n", b[0]);}void_float () {puts("");puts("float:");puts("");memsetC0xfd,sizeofc);printf("%f\n", c[0]);memsetC0xFE,sizeofc);printf("%f\n", c[0]);memsetC0xFF,sizeofc);printf("%f\n", c[0]);puts("");memsetC0xCD,sizeofc);printf("%f%f\n", c[0],c[0]*2);memsetC0xce,sizeofc);printf("%f%f\n", c[0],c[0]*2);memsetC0XCF,sizeofc);printf("%f%f\n", c[0],c[0]*2);puts("");memsetC0x4e,sizeofc);printf("%f%f\n", c[0],c[0]*2);memsetC0x4f,sizeofc);printf("%f%f\n", c[0],c[0]*2);memsetC0x50,sizeofc);printf("%f%f\n", c[0],c[0]*2);puts("");memsetC0x7e,sizeofc);printf("%.15f\n", c[0]);memsetC0x7f,sizeofc);printf("%.15f\n", c[0]);memsetC0x80,sizeofc);printf("%.15f\n", c[0]);}void_double () {puts("");puts("Double:");puts("");memset(d,0xfd,sizeofD);printf("%lf\n", d[0]);memset(d,0xFE,sizeofD);printf("%lf\n", d[0]);memset(d,0xFF,sizeofD);printf("%lf\n", d[0]);puts("");memset(d,0xc1,sizeofD);printf("%lf%lf\n", d[0],d[0]*2);memset(d,0xc2,sizeofD);printf("%lf%lf\n", d[0],d[0]*2);memset(d,0xc3,sizeofD);printf("%lf%lf\n", d[0],d[0]*2);puts("");memset(d,0x42,sizeofD);printf("%lf%lf\n", d[0],d[0]*2);memset(d,0x43,sizeofD);printf("%lf%lf\n", d[0],d[0]*2);memset(d,0x44,sizeofD);printf("%lf%lf\n", d[0],d[0]*2);puts("");memset(d,0x7e,sizeofD);printf("%lf\n", d[0]);memset(d,0x7f,sizeofD);printf("%lf\n", d[0]);memset(d,0x80,sizeofD);printf("%lf\n", d[0]);}intMain () {_int ();    _long ();    _float (); _double ();}

"Self-use" memset for int, long long, float, double extremum how Clear