倍增练习题。

基环树上倍增一下维护维护最小值和权值和,注意循环的时候$j$这维作为状态要放在外层循环,平时在树上做的时候一个一个结点处理并不会错,因为之前访问的结点已经全部处理过了。

时间复杂度$O(nlogk)$。

Code:

#include <cstdio>
#include <cstring>
using namespace std;
typedef long long ll; const int N = 1e5 + ;
const int Lg = ;
const int inf = 0x3f3f3f3f; int n, to[N][Lg];
ll stp, val[N], sum[N][Lg], minn[N][Lg]; template <typename T>
inline void read(T &X) {
X = ; char ch = ; T op = ;
for(; ch > ''|| ch < ''; ch = getchar())
if(ch == '-') op = -;
for(; ch >= '' && ch <= ''; ch = getchar())
X = (X << ) + (X << ) + ch - ;
X *= op;
} template <typename T>
inline void chkMin(T &x, T y) {
if(y < x) x = y;
} template <typename T>
inline T min(T x, T y) {
return x > y ? y : x;
} inline void solve(int x) {
ll resSum = 0LL, resMin = inf, tmp = stp;
for(int i = ; i >= ; i--)
if((tmp >> i) & ) {
resSum += sum[x][i];
chkMin(resMin, minn[x][i]);
x = to[x][i];
}
printf("%lld %lld\n", resSum, resMin);
} int main() {
read(n), read(stp);
for(int i = ; i <= n; i++) read(to[i][]), to[i][]++;
for(int i = ; i <= n; i++) read(val[i]); memset(minn, 0x3f, sizeof(minn));
for(int i = ; i <= n; i++)
sum[i][] = minn[i][] = val[i];
for(int j = ; j <= ; j++)
for(int i = ; i <= n; i++)
{
to[i][j] = to[to[i][j - ]][j - ];
minn[i][j] = min(minn[i][j - ], minn[to[i][j - ]][j - ]);
sum[i][j] = sum[i][j - ] + sum[to[i][j - ]][j - ];
} /* for(int i = 1; i <= n; i++)
printf("%lld ", sum[i][1]);
printf("\n"); */ for(int i = ; i <= n; i++) solve(i); return ;
}
05-11 19:59