求助，60分

BismarkSea @ 2023-07-16 23:04:06

#include <iostream>
long long f[21][21][21];
long long w(long long a, long long b, long long c) {

    if (f[a][b][c] != 0)return f[a][b][c];
    else if (a == 0 || b == 0 || c == 0)f[a][b][c] = 1;
    else if (a < b && b < c)f[a][b][c] = w(a, b, c - 1) + w(a, b - 1, c - 1) - w(a, b - 1, c);
    else f[a][b][c] = w(a - 1, b, c) + w(a - 1, b - 1, c) + w(a - 1, b, c - 1) - w(a - 1, b - 1, c - 1);
    return f[a][b][c];
}
int main(){
    using namespace std;
    long long a = 0, b = 0, c = 0;
    while (1) {
        cin >> a>>b>>c;
        if (a == -1&&b==-1&&c==-1)break;
        printf("w(%lld, %lld, %lld) = ",a, b, c);
        if (a < 0)a = 0; if (b < 0)b = 0; if (c < 0)c = 0;
        if (a > 20 || b > 20 || c >20) {a=20;b = 20; c = 20;}
        printf("%lld\n", w(a, b, c));
    }
    return 0;
}

by Misophiliac @ 2023-07-16 23:21:13

@BismarkSea

#include <iostream>
long long f[21][21][21];
long long w(long long a, long long b, long long c) {
    if (a <= 0 || b <= 0 || c <= 0) return 1;
    if (a > 20 || b > 20 || c > 20) return w(20, 20, 20);
    if (f[a][b][c] != 0)return f[a][b][c];
    if (a < b && b < c)f[a][b][c] = w(a, b, c - 1) + w(a, b - 1, c - 1) - w(a, b - 1, c);
    else f[a][b][c] = w(a - 1, b, c) + w(a - 1, b - 1, c) + w(a - 1, b, c - 1) - w(a - 1, b - 1, c - 1);
    return f[a][b][c];
}
int main(){
    using namespace std;
    long long a = 0, b = 0, c = 0;
    while (1) {
        cin >> a>>b>>c;
        if (a == -1&&b==-1&&c==-1)break;
        printf("w(%lld, %lld, %lld) = ",a, b, c);
        printf("%lld\n", w(a, b, c));
    }
    return 0;
}

by BismarkSea @ 2023-07-17 12:35:54

AC了，谢谢大佬