poj 1487 Single-Player Games

#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<vector>
#define ll __int64
#define pi acos(-1.0)
#define SIZE 1024
using namespace std;
const double eps=1e-8;
inline bool zero(double x)
{
return fabs(x)<eps;
}
struct node
{
int type,val;
node(){}
node(int _type,int _val){
type=_type;
val=_val;
}
}an[SIZE];
vector<int> g[SIZE];
double mat[32][32];
int n,ind;
char *p;
void build(int now)
{
int t,m;
while(*p){
while(*p==' '&&*p) p++;
if(!*p) break;
if((*p>='0'&&*p<='9')||*p=='-'){
ind++;
sscanf(p,"%d%n",&t,&m);
p+=m;
an[ind]=node(0,t);
g[now].push_back(ind);
}
else if(*p=='(')
{
ind++;
an[ind]=node(-1,0);
p++;
g[now].push_back(ind);
build(ind);
}
else if(*p==')')
{
p++;
return;
}
else{
ind++;
an[ind]=node(1,*p-'a');
p++;
g[now].push_back(ind);
}
}
}
void toMat(int now,double tp,int var)
{
double p;
if(g[now].size()) p=tp/g[now].size();
for(int i=0;i<(int)g[now].size();i++){
int x=g[now][i];
if(an[x].type==-1)
toMat(x,p,var);
else{
if(an[x].type==0)
mat[var]
+=an[x].val*p;
else{
mat[var][an[x].val]-=p;
}
}
}
}
void init()
{
ind=0;
memset(an,0,sizeof(an));
for(int i=0;i<SIZE;i++) g[i].clear();
}
void Gauss_line(int a,int b,int col)
{
double mul_a=mat[a][col];
double mul_b=mat[b][col];
for(int i=0;i<=n;i++)
mat[b][i]=mat[b][i]-mat[a][i]*mul_b/mul_a;
}
void Gauss()
{
for(int row=0,col=0;row<n&&col<n;row++,col++){
int ptr=-1;
for(int i=row;i<n;i++)
if(!zero(mat[i][col])){
ptr=i;
break;
}
if(ptr==-1) continue;
else{
for(int i=0;i<=n;i++)
swap(mat[row][i],mat[ptr][i]);
for(int i=0;i<n;i++)
if(i!=row)
Gauss_line(row,i,col);
}
}
}
double getans(int x)
{
return mat[x]
/mat[x][x];
}
bool check(int x)
{
for(int i=0;i<n;i++)
if(i!=x&&!zero(mat[x][i]))
return false;
return !zero(mat[x][x]);
}
int main(){
int m,i,j,t=1;
char cmd[SIZE];
while(cin>>n&&n){
memset(mat,0,sizeof(mat));
printf("Game %d\n",t++);
for(int i=0;i<n;i++){
init();
do{
gets(cmd);
}while(*cmd=='\0');
p=cmd;
while(*p!='(') p++;
build(0);
toMat(0,1.,i);
mat[i][i]+=1.0;
}
Gauss();
for(i=0;i<n;i++){
if(check(i))
printf("Expected score for %c = %.3lf\n",'a'+i,getans(i));
else
printf("Expected score for %c undefined\n",'a'+i);
}
printf("\n");
}
return 0;
}