A，B，C水题

D还是搜索，枚举每个木棍最后合成到ABC中的哪个或不合成

E

超级马农

枚举点+哈希

#include <bits/stdc++.h>
using namespace std;
int n, a[1005][1005], s1[1005][1005], s2[1005][1005], t[20000005], ans;
int main() {
    cin >> n;
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) cin >> a[i][j];
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            s1[i][j] = s1[i - 1][j] + s1[i][j - 1] - s1[i - 1][j - 1] + a[i][j];
        }
    }
    for (int i = n; i >= 1; i--) {
        for (int j = n; j >= 1; j--) {
            s2[i][j] = s2[i + 1][j] + s2[i][j + 1] - s2[i + 1][j + 1] + a[i][j];
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            for (int h = 1; h <= i; h++) {
                for (int o = 1; o <= j; o++) {
                    //                  if(i==2&&j==2&&h==2&&o==1)
                    //cout<<s1[i][j]-s1[h-1][j]-s1[i][o-1]+s1[h-1][o-1]<<endl;
                    t[s1[i][j] - s1[h - 1][j] - s1[i][o - 1] + s1[h - 1][o - 1] + 10000000]++;
                }
            }
            for (int h = i + 1; h <= n; h++) {
                for (int o = j + 1; o <= n; o++) {
                    //                  if(i==2&&j==2&&h==3&&o==3)
                    //cout<<s2[i+1][j+1]-s2[h+1][j+1]-s2[i+1][o+1]+s2[h+1][o+1]<<endl;
                    ans += t[s2[i + 1][j + 1] - s2[h + 1][j + 1] - s2[i + 1][o + 1] + s2[h + 1][o + 1] +
                             10000000];
                }
            }
            for (int h = 1; h <= i; h++) {
                for (int o = 1; o <= j; o++) {
                    t[s1[i][j] - s1[h - 1][j] - s1[i][o - 1] + s1[h - 1][o - 1] + 10000000]--;
                }
            }
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            s1[i][j] = s2[i][j] = 0;
        }
    }
    for (int i = 1; i <= n / 2; i++) {
        for (int j = 1; j <= n; j++) {
            swap(a[i][j], a[n - i + 1][j]);
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            s1[i][j] = s1[i - 1][j] + s1[i][j - 1] - s1[i - 1][j - 1] + a[i][j];
        }
    }
    for (int i = n; i >= 1; i--) {
        for (int j = n; j >= 1; j--) {
            s2[i][j] = s2[i + 1][j] + s2[i][j + 1] - s2[i + 1][j + 1] + a[i][j];
        }
    }
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++) {
            for (int h = 1; h <= i; h++) {
                for (int o = 1; o <= j; o++) {
                    //                  if(i==2&&j==2&&h==2&&o==1)
                    //cout<<s1[i][j]-s1[h-1][j]-s1[i][o-1]+s1[h-1][o-1]<<endl;
                    t[s1[i][j] - s1[h - 1][j] - s1[i][o - 1] + s1[h - 1][o - 1] + 10000000]++;
                }
            }
            for (int h = i + 1; h <= n; h++) {
                for (int o = j + 1; o <= n; o++) {
                    //                  if(i==2&&j==2&&h==3&&o==3)
                    //cout<<s2[i+1][j+1]-s2[h+1][j+1]-s2[i+1][o+1]+s2[h+1][o+1]<<endl;
                    ans += t[s2[i + 1][j + 1] - s2[h + 1][j + 1] - s2[i + 1][o + 1] + s2[h + 1][o + 1] +
                             10000000];
                }
            }
            for (int h = 1; h <= i; h++) {
                for (int o = 1; o <= j; o++) {
                    t[s1[i][j] - s1[h - 1][j] - s1[i][o - 1] + s1[h - 1][o - 1] + 10000000]--;
                }
            }
        }
    }
    cout << ans;
    return 0;
}

F

终态枚举+贪心

#include <bits/stdc++.h>
using namespace std;
int n, a[10000], b[10000], v[2005][2005], tt[2005], ans = 1e9;  // v[i][0]有几个
int main() {
    scanf("%d", &n);
    for (int i = 2; i <= n; i++) {
        scanf("%d", &a[i]);
    }
    for (int i = 2; i <= n; i++) {
        scanf("%d", &b[i]);
        v[a[i]][0]++;
        v[a[i]][v[a[i]][0]] = b[i];
    }
    for (int i = 1; i <= n; i++) {
        if (v[i][0]) {
            sort(v[i] + 1, v[i] + v[i][0] + 1);
        }
    }
    int aans = 0, cnt = 0;
    for (int i = 1; i <= n; i++) {
        aans = 0, cnt = 0;
        tt[0] = 0;
        for (int j = 2; j <= n; j++) {
            int k;
            for (k = 1; k < v[j][0] + 2 - i; k++) {
                aans += v[j][k], cnt++;
            }
            for (; k <= v[j][0]; k++) {
                tt[0]++;
                tt[tt[0]] = v[j][k];
            }
        }
        if (tt[0]) {
            sort(tt + 1, tt + tt[0] + 1);
        }
        for (int j = 1; j <= i - v[1][0] - cnt; j++) {
            aans += tt[j];
        }
        ans = min(aans, ans);
    }
    cout << ans;
    return 0;
}