Luogu1769 淘汰赛制_NOI导刊2010提高（01）（概率DP）

第(i)次位置在(pos_0 / 2^{i - 1})

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for(register int  a = (b); a <= (c); ++ a)
#define nR(a,b,c) for(register int  a = (b); a >= (c); -- a)
#define Max(a,b) ((a) > (b) ? (a) : (b))
#define Min(a,b) ((a) < (b) ? (a) : (b))
#define Fill(a,b) memset(a, b, sizeof(a))
#define Abs(a) ((a) < 0 ? -(a) : (a))
#define Swap(a,b) a^=b^=a^=b
#define ll long long

#define ON_DEBUG

#ifdef ON_DEBUG

#define D_e_Line printf("

----------

")
#define D_e(x)  cout << #x << " = " << x << endl
#define Pause() system("pause")
#define FileOpen() freopen("in.txt","r",stdin);

#else

#define D_e_Line ;
#define D_e(x)  ;
#define Pause() ;
#define FileOpen() ;

#endif

struct ios{
    template<typename ATP>ios& operator >> (ATP &x){
        x = 0; int f = 1; char c;
        for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-')  f = -1;
        while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();
        x*= f;
        return *this;
    }
}io;
using namespace std;

double f[11][2027];
int won[2027][2027];
int main(){
    int n;
    io >> n;
    int m = 1 << n;
    R(i,1,m){
    	R(j,1,m){
    		io >> won[i][j];
    	}
    }
    R(i,1,m){
    	f[0][i] = 1;
    }
    R(i,1,n){
    	R(j,1,m){
    		int pos = ceil((double)j / (double)(1 << (i - 1)));
    		pos = (pos & 1) ? pos + 1 : pos - 1;
			R(k, pos * (1 << (i - 1)) - (1 << (i - 1)) + 1, pos * (1 << (i - 1))) {
				f[i][j] += f[i - 1][j] * won[j][k] / 100 * f[i - 1][k];
			}
    		
    	}
    }
    
    double maxx = 0.0;
    int ans;
    R(i,1,m){
    	if(f[n][i] > maxx){
    		maxx = f[n][i];
    		ans = i;
    	}
    }
    
    printf("%d", ans);
    return 0;
}