Submission #8194036

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Source Code Expand

// ※※※ 解答不能 ※※※
// square1001氏.
// https://atcoder.jp/contests/dwango2015-prelims/submissions/1991686
#include <bits/stdc++.h>
using namespace std;
int n, inf = 1012345678; double comb[109][109], dp[109];
int main(){
    scanf("%d", &n);
    comb[0][0] = 1.0;
    for(int i = 1; i <= n; i++){
        for(int j = 0; j <= i; j++){
            comb[i][j] = comb[i - 1][j];
            if(j >= 1) comb[i][j] += comb[i - 1][j - 1];
        }
    }
    double mul = 3.0;
    for(int i = 2; i <= n; i++){
        mul *= 3.0;
        double all = 0;
        for(int a = 0; a <= i; a++){
            for(int b = 0; a + b <= i; b++){
                int c = i - a - b;
                int d = min({ a ? a : inf, b ? b : inf, c ? c : inf });
                double s = comb[i][a] * comb[i - a][b];
                if((a == 0) + (b == 0) + (c == 0) == 2 || (d == a && d == b && d == c)) all += s;
                else                                                                    dp[i] += dp[d] * s;
            }
        }
        dp[i] /= mul - all;
        dp[i] += mul / (mul - all);
    }
    printf("%.15lf\n", dp[n]);
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:8:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^

Judge Result