有没有好心人帮蒟蒻看看为肾摸会RE

Rt，我用分块写的，吸完氧之后拿到了\texttt{63pts}，然后其余的点没有TLE，全是RE。。。

有没有好心人帮蒟蒻看看RE的原因啊QAQ，看了好久都没看出来哪里能导致RE QAQ：

#include<bits/stdc++.h>
using namespace std;
int n,m,opt,x,y,L[1005],R[1005],sum[1005],maxx[1005],zj[1005],yj[1005],a[600005],bel[600005],siz;
int sum1,sum2,ans;
inline int mymax(int qaq,int qwq) {
    return qaq>qwq?qaq:qwq;
}
int main() {
    fill(maxx+1,maxx+1001,-0x7fffffff);
    fill(zj+1,zj+1001,-0x7fffffff);
    fill(yj+1,yj+1001,-0x7fffffff);
    scanf("%d%d",&n,&m);
    siz=sqrt(ceil(n));
    for(int i=1; i<=n; i++) scanf("%d",a+i);
    for(int i=1; i<=siz; i++) {
        L[i]=(i-1)*siz+1;
        R[i]=i*siz;
        sum1=sum2=0;
        for(int j=L[i]; j<=R[i]; j++) {
            maxx[i]=mymax(maxx[i],a[j]);
            sum[i]+=a[j];
            bel[j]=i;
            sum1+=a[j];
            zj[i]=mymax(zj[i],sum1);
            if(sum2+a[j]>0) {
                sum2+=a[j];
                maxx[i]=mymax(maxx[i],sum2);
            } else sum2=mymax(0,a[j]);
        }
        sum1=0;
        for(int j=R[i]; j>=L[i]; j--) {
            sum1+=a[j];
            yj[i]=mymax(yj[i],sum1);
        }
    }
    while(m--) {
        scanf("%d",&opt);
        if(opt==1) {
            ans=-0x7fffffff;
            scanf("%d%d",&x,&y);
            if(x>y) swap(x,y);
            if(bel[x]==bel[y]){
                sum1=0; 
                for(int i=x;i<=y;i++){
                    ans=mymax(ans,a[i]);
                    if(sum1+a[i]>=0){
                        sum1+=a[i];
                        ans=mymax(ans,sum1);    
                    }
                    else sum1=mymax(0,a[i]);
                }
            }
            else{
                int tmpx=x,tmpy=y,now=0;
                for(;tmpx!=L[bel[tmpx]];++tmpx);
                for(;tmpy!=R[bel[tmpy]];--tmpy);
                tmpx=bel[tmpx];
                tmpy=bel[tmpy];
                for(;x!=L[bel[x]];++x){
                    ans=mymax(ans,a[x]);
                    if(now+a[x]>=0){
                        now+=a[x];
                        ans=mymax(ans,now); 
                    }
                    else now=mymax(0,a[x]);
                }
                for(int i=tmpx;i<=tmpy;i++){
                    ans=mymax(maxx[i],ans);
                    ans=mymax(now+zj[i],ans);
                    now=mymax(0,mymax(yj[i],now+sum[i]));
                }
                for(int i=R[tmpy]+1;i<=y;i++){
                    ans=mymax(ans,a[i]);
                    if(now+a[i]>=0){
                        now+=a[i];
                        ans=mymax(ans,now); 
                    }
                    else now=mymax(0,a[i]);
                }
            }
            printf("%d\n",ans);
        } else {
            scanf("%d%d",&x,&y);
            a[x]=y;
            sum[bel[x]]=sum1=sum2=0;
            maxx[bel[x]]=zj[bel[x]]=yj[bel[x]]=-0x7fffffff;
            for(int j=L[bel[x]]; j<=R[bel[x]]; j++) {
                maxx[bel[x]]=mymax(maxx[bel[x]],a[j]);
                sum[bel[x]]+=a[j];
                sum1+=a[j];
                zj[bel[x]]=mymax(zj[bel[x]],sum1);
                if(sum2+a[j]>=0) {
                    sum2+=a[j];
                    maxx[bel[x]]=mymax(maxx[bel[x]],sum2);
                } else sum2=0;
            }
            sum1=0;
            for(int j=R[bel[x]]; j>=L[bel[x]]; j--) {
                sum1+=a[j];
                yj[bel[x]]=mymax(yj[bel[x]],sum1);
            }
        }
    }
}