# including "iostream"
Use namespace std
# contains "cmath"
void main()
{
int i=0，j = 0；
double thita[8]={ 1.5708，0.7854，0，-0.7854，- 1.5708，-2.3562，-3. 14 16，-3.927}，
S=0.4 142，
a，B，E，
I[8][8]，ln[8]，aatan[8]；
for(I = 0； I < = 7; i++)
{
for(j = 0； j & lt=7; j++)
{
If (i==j)
I[I][j]= 3. 14 16；
other
{
a = 0-(x[I]-a[j])* cos(thita[j])-(y[I]-b[j])* sin(thita[j])；
b =(x[I]-a[j])*(x[I]-a[j])+(y[I]-b[j])*(y[I]-b[j])；
e =(x[I]-a[j])* sin(thita[j])-(y[I]-b[j])* cos(thita[j])；
ln[j]= log( 1+(S * S+2 * A * S)/B)；
aatan[j]= atan((S+A)/E)-atan(A/E)；
I[I][j]= 0.5 * sin(thita[I]-thita[j])* ln[j]-cos(thita[I]-thita[j])* aatan[j]；
}
Extended data:
Most input/output (I/O) operations under Win32 have two forms: synchronous or asynchronous. It has been proved that in many cases, multi-thread design using synchronous I/O can be simulated by using asynchronous single-thread I/O. This paper does not discuss asynchronous single-threaded I/O as an alternative to multithreading, but suggests that both designs should be considered at the same time.
Note that the design of Win32 I/O system provides some mechanisms to make asynchronous I/O better than synchronous I/O (for example, I/O completion port). I plan to discuss synchronous I/O and asynchronous I/O in future articles.
Baidu Encyclopedia -Win32 Multithreading