nextt数组表示这个位置的下一个位置。
cnt数组表示这个位置 i 到nextt[i]可以弹几次。
end[i] 表示在从 i 弹出去的情况下， 最后一个位置是哪里。
然后就看代码吧。
#include <iostream>
#include <vector>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <queue>
#include <stack>
#include <bitset>
using namespace std;
#define pb(x) push_back(x)
#define ll long long
#define mk(x, y) make_pair(x, y)
#define lson l, m, rt<<1
#define mem(a) memset(a, 0, sizeof(a))
#define rson m+1, r, rt<<1|1
#define mem1(a) memset(a, -1, sizeof(a))
#define mem2(a) memset(a, 0x3f, sizeof(a))
#define rep(i, n, a) for(int i = a; i<n; i++)
#define fi first
#define se second
typedef pair<int, int> pll;
const double PI = acos(-1.0);
const double eps = 1e-;
const int mod = 1e9+;
const int inf = ;
const int dir[][] = { {-, }, {, }, {, -}, {, } };
const int maxn = 1e5 + ;
int a[maxn], cnt[maxn], nextt[maxn], pos[maxn], block[maxn], n;
void update(int x, int y) {
if(y >= n) {
nextt[x] = n+;
cnt[x] = ;
pos[x] = x;
} else {
if(block[x] == block[y]) {
nextt[x] = nextt[y];
cnt[x] = cnt[y] + ;
} else {
nextt[x] = y;
cnt[x] = ;
}
pos[x] = pos[y];
}
}
void query(int x) {
int i, ans = ;
for(i = x; ; i = nextt[i]) {
ans += cnt[i];
if(nextt[i] >= n) {
i = pos[i];
break;
}
}
printf("%d %d\n", i+, ans);
}
int main()
{
int m, sign, x, y;
cin>>n>>m;
int BLOCK = sqrt(n);
for (int i = ; i < n; i++) {
scanf("%d", a + i);
block[i] = i / BLOCK;
}
for (int i = n-; i >= ; i--) {
update(i, i + a[i]);
}
while (m--) {
scanf("%d", &sign);
if(sign) {
scanf("%d", &x);
query(x-);
} else {
scanf("%d%d", &x, &y);
x--;
a[x] = y;
int l = block[x] * BLOCK;
int r = l + BLOCK;
r = min(n, r);
for(int i = r-; i >= l; i--) {
update(i, i + a[i]);
}
}
}
return ;
}