C / C++ / MFC

import numpy as np
from pylab import *
import sys
import copy
import matplotlib.pyplot as plt
import matplotlib.ticker as ticker
L =[[]for i in range(2)]
N=int(input("Enter a number N for N x N grid: "))
h=1/N
def clear_list1():
    L[1].clear()
    L[0].clear()
iterat=0
error=0.75
clear_list1()
xx=np.arange(0,N,h)
yy=np.arange(0,N,h)
x,y = np.meshgrid(xx,yy)
phi= copy.deepcopy((x**2-y**2))
phi[1:-1,1:-1]=0
phi_new = copy.deepcopy(phi)
resid=np.zeros((N,N))


while True:
    if iterat<21:

       for w in np.linspace(1,2,11):
           for i in range(1,N-1):
               for j in range(1,N-1):
                   phi1=(phi[i+1,j]+phi[i-1,j]+phi[i,j+1]+phi[i,j-1])/4
                   phi[i,j]=w*phi1+(1-w)*phi1
                   
       Sumresidual=0
       for i in range(1,N-1):
           for j in range(1,N-1):
               resid[i,j]= -4*phi[i,j]+phi[i+1,j]+phi[i-1,j]+phi[i,j+1]+phi[i,j-1]
               Sumresidual=Sumresidual+(resid[i,j])**2
    else:
        break
    iterat=iterat+1
    p=np.sqrt(Sumresidual)
    L[0].append(p)
    L[1].append(w)

ax = plt.axes()
ax.xaxis.set_major_locator(ticker.MaxNLocator(5))

plt.plot(L[0],L[1])
plt.yscale('log')
plt.xlabel('w')
plt.ylabel('|| residual ||')
plt.title('effect of w on residual')
plt.show()

   int Imax = 10;
      for ( int I=0; I<imax; i++="" )="" {

="" for="" (int="" iy="0;" iy<ny;="" iy++)="" {
="" ix="0;" ix<nx;="" ix++)="" float="" v1="v[(iy*nx+ix)*nz];
" int="" k1="0;
" k0="0;
" jstart="0;
" while="" (k1="" <="" nz)="" k;
="" (k="k1;" k<nz;="" k++)="" v2="v[(iy*nx+ix)*nz" +="" k];

="" if="" (="" 100.="" *="" fabs(v2="" -v1)="">= sharpeningThreshold_percentage/2. && jstart == 0 ) {
          k0 = k;
          jstart = 1;
        }


        if ( 100. * fabs(v2 -v1) / v1 >= sharpeningThreshold_percentage ) {
          v1     = v2;
          k1     = k;
          jstart = 0;
          for ( int kk=k0; kk<=k; kk++ )
            v[(iy*nx+ix)*nz + kk] = v1;
          k0 = k1;
          break;
        }
        v[(iy*nx+ix)*nz + k] = v1;
          }
          if ( k >= nz-1 )
        break;
        }
      }
    }

    if ( I < Imax-1 )
      smooth(10, 1, v, nx, ny, nz);
   
      } // sharpening -smoothing I-loop closed

    } // if sharpeningThreshold_percentage  closed

  }

#include <stdio.h>

void calc(void *var) {
	//try convert short to int with new var
	int tmp = *(int*)var;
	printf("tmp: %i\n", tmp);//bad, must be 30002
	//try cast/convert original var
	*(int*)var += 30003;
}

void complexeShortToInt() {
	short int vInt2 = 30002;
	calc(&vInt2);
	printf("complexeShortToInt: %i\n", vInt2);//bad, must be 60005
}

/*void simpleShortToInt() {
	short int vInt = 30000;
	int vOut = (int)vInt;
	vOut += 30000;
	printf("simpleShortToInt: %i\n", vOut);//good
}*/

int main() {
	//simpleShortToInt();//good
	complexeShortToInt();//bad
	return 0;
}