BZOJ3680 JSOI2004 Equilibrium Point-stochastic/approximate algorithm

The iteration was messed up and it was over ...

#include <bits/stdc++.h>using namespacestd;Doublex[10005],y[10005],w[10005];DoubleXm,ym,wt,k,lambda=0.9;intN;Const Doubleox[5]={0,1,0,-1,0},oy[5]={0,0,1,0,-1};DoubleCalcDoubleXwDoubleyw) {    Doubleans=0;  for(intI=1; i<=n;i++) ans+=sqrt ((Xw-x[i]) * (Xw-x[i]) + (Yw-y[i]) * (yw-y[i)) *W[i]; returnans;}intMain () {CIN>>N;  for(intI=1; i<=n;i++) Cin>>x[i]>>y[i]>>W[i], XM+=x[i]*w[i], ym+=y[i]*W[i], K=Max (K,max (ABS (X[i), ABS (Y[i))), WT+=W[i]; XM/=wt; Ym/=wt; K*=0.1; Doublez=0, oz=-1e+8;  while(k>=0.0001) {        //printf ("%.3f%.3f k=%.4f\n", xm,ym,k);oz=Z; DoubleMinopt=1e+ -; intopt=0;Doubletmp;  for(intI=0; i<=4; i++) {tmp=calc (xm+ox[i]*k,ym+oy[i]*k); if(tmp<minopt) minopt=tmp, opt=i; } XM+=ox[opt]*k, ym+=oy[opt]*K; Z=tmp; K*=Lambda; } printf ("%.3f%.3f\n", Xm,ym); }

BZOJ3680 JSOI2004 Equilibrium Point-stochastic/approximate algorithm