for (int it=0; it<N-1; it++){       x[it]= x[it]+vx[it]*dt;       y[it]= y[it]+vy[it]*dt;       // Choque con las paredes       if ( x[it]<0 || x[it]>L) {            x[it] =x[it]-vx[it]*dt;            vx[it]=-vx[it];            }       if ( y[it]<0 || y[it]>L) {            y[it] =y[it]-vy[it]*dt;            vy[it]=-vy[it];            }

for (int jt=it+1; jt<N; jt++){       rij=Math.sqrt( Math.pow(x[it]-x[jt],2.) + Math.pow(y[it]-y[jt],2.));        //Choque       if (rij<2*R) {            vcmx=(vx[it]+vx[jt])/2.;            vcmy=(vy[it]+vy[jt])/2.;            vpxi= vx[it] - vcmx;            vpyi= vy[it] - vcmy;            xij = x[jt] - x[it];            yij = y[jt] - y[it];            pe = vpxi*xij + vpyi*yij;            if(pe>0) {                      vpxin = vpxi - 2.* (vpxi*xij + vpyi*yij) / (rij*rij) * xij;                      vpyin = vpyi - 2.* (vpxi*xij + vpyi*yij) / (rij*rij) * yij;                      vx[it] = vcmx + vpxin;                      vy[it] = vcmy + vpyin;                      vx[jt] = vcmx - vpxin;                      vy[jt] = vcmy - vpyin;                      }                 }          } }

Autora: Mª José Nuñez