倒序處理，線段樹保存有多少空位

#include <iostream>
#include <cstdio>
using namespace std;
int n, ans[200005], uu[200005], vv[200005];
struct SGT{
    int sum[800005];
    void build(int o, int l, int r){
        if(l==r)    sum[o] = 1;
        else{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int
 
 rson=lson|1;
            if(l<=mid)  build(lson, l, mid);
            if(mid<r)   build(rson, mid+1, r);
            sum[o] = sum[lson] + sum[rson];
        }
    }
    void update(int o, int l, int r, int x, int y){
        if(l==r){
            ans[l] = y;
            sum[o] = 0;
        }
        else
 
{
            int mid=(l+r)>>1;
            int lson=o<<1;
            int rson=lson|1;
            if(sum[lson]>x) update(lson, l, mid, x, y);
            else    update(rson, mid+1, r, x-sum[lson], y);
            sum[o] = sum[lson] + sum[rson];
        }
    }
}sgt;
int main(){
    while
 
(scanf("%d", &n)!=EOF){
        sgt.build(1, 1, n);
        for(int i=1; i<=n; i++)
            scanf("%d %d", &uu[i], &vv[i]);
        for(int i=n; i; i--)
            sgt.update(1, 1, n, uu[i], vv[i]);
        for(int i=1; i<=n; i++)
            printf("%d ", ans[i]);
        printf("\n");
    }
    return 0;
}

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