题目 在题目讨论版里面发了没人回啊。

#include<bits/stdc++.h>
const int maxn=1e6+5;
using namespace std;
int n,heap[maxn],t,a[maxn],s,ans;
void down(int i,int n){
    while(i*2<=n){
        int T=i*2;
        if(T<n&&heap[T]>heap[T+1])
            T++;
        if(heap[i]>heap[T]){
            swap(heap[i],heap[T]);
            i=T;
        } else
            break;
    }
}
int main(){
    scanf("%d%d",&t,&n);
    ans=n;
    for(int i=1;i<=n;i++){
        scanf("%d",&a[i]);
        heap[i]=a[i];
    }
    t--;
    while(1){
        if(ans==1)
            break;
        if(heap[ans]-heap[1]<=heap[2])
            break;
        heap[1]=heap[ans--]-heap[1];
        down(1,ans);
    }
    printf("%d\n",ans);
    while(t--){
        ans=n;
        scanf("%d",&s);
        for(int i=1,k,t;i<=s;i++){
            scanf("%d%d",&k,&t);
            a[k]=t;
        }
        for(int i=1;i<=n;i++)
            heap[i]=a[i];
        while(1){
            if(ans==2)
                ans--;
            if(ans==1)
                break;
            if(heap[ans]-heap[1]<=heap[2])
                break;
            heap[1]=heap[ans--]-heap[1];
            down(1,ans);
        }
        printf("%d\n",ans);
    }
    return 0;
}