3
: ('+'), ('-'), ('*') ('/'). . .
('/') . , . , . , x , y . :
| x = 7 / 3; | x = 2 |
| y = 7 / 3; | y = 2.000000 |
| y = 7.0 / 3; | y = 2.333333 |
| y = (double)7 / 3; | y = 2.333333 |
. , , . , 7/3 2. 2 2.000000 y.
. .
1.1.1. a b.
(a + b)/2 . . . , : res = (a + b)/2.0. :
#include < stdio.h >
int a=3,b=7;
double res;
void main(void)
{
| x = 6 % 3 | x = 0 |
| x = 8 % 3 | x = 2 |
| x = -6 % 3 | x = 0 |
| x = -8 % 3 | x = -2 |
/*scanf("%d %d",&a,&b);*/
res = (a + b) / 2.0;
printf("%lf\n",res);
}
| i = i + 1 | i++ |
| i = i - 1 | i-- |
| i = i + a | i += a |
| i = i %a1 | i %= a |
'%'. ( n 0 n 1 ).
. , i = i + 1 i ++. < op > , i = i < op > a i < op >= a. :
1.1.2. h: m, h , m . , h 1: m 1 , h 2: m 2 (0 ≤ h 1, h 2 ≤ 23, 0 ≤ m 1, m 2 ≤ 59). , (hres: mres) . , 24 .
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h 1: m 1 h 2: m 2, , . , h 1: m 1 = 23:50 h 2: m 2 = 13:20, 13 30 .
h: m h *60 + m , . , time 1 = h 1 * 60 + m 1 , time 2 = h 2 * 60 + m 2 . timeRes = (time 2 time 1 + 24 * 60) % (24 * 60) . timeRes .
#include < stdio.h >
int h1, h2, m1, m2, time1, time2, timeRes, hres, mres;
void main(void)
{
h1 = 23; m1 = 50; h2 = 13; m2 = 20;
time1 = h1 * 60 + m1; time2 = h2 * 60 + m2;
timeRes = (time2 - time1 + 24 * 60) % (24 * 60);
hres = timeRes / 60; mres = timeRes % 60;
printf("%d:%d\n",hres,mres);
}
1.1.1. , m . n ?
1.1.2. . , n , m ?
1.1.3. n . a, b, c , n.
1.1.1. , (m + n 1) / n.
1.1.2. , m / n.
'' ('and'), '' ('or'), '' ('not') 2 ('xor'). :
| x and y | x && y |
| x or y | x || y |
| not x | ! x |
| x xor y | x ^ y |
:
| x | y | X and y | x | y | x or y | x | not x | x | y | x xor y | |||
, . (x == y) !(x xor y). " 2", x xor y = (x + y) mod 2. -:
not (x and y) = (not x) or (not y)
!(x && y) =! x ||! y
1.2.1. :
1. : x = y;
2. : x imp y = (not x) or y
. ( , ). 
.
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, . , , , . . , .
