内存最优

击败了100.00的人 3.25MB

#include<cstdio>
const int N=5e5+1;
typedef int ll;
ll c[N]; 
int n,m,op,x,y,k;
inline int lowbit(ll x){return x&-x;}
inline void update(ll x,ll v){while(x<=n)c[x]+=v,x+=lowbit(x);}
inline ll sum(ll x){
    ll ans=0;
    while(x>0)ans+=c[x],x-=lowbit(x);
    return ans;
}
int main(){
    scanf("%d%d",&n,&m);
    ll last=0,now;
    for(int i=1;i<=n;i++){
        scanf("%d",&now);
        update(i,now-last);  // 直接计算差分
        last=now;
    }
    while(m--){
        scanf("%d",&op);
        if(op==1){
            scanf("%d%d%d",&x,&y,&k);
            update(x,k);
            update(y+1,-k);
        }else{
            scanf("%d",&x);
            printf("%d\n",sum(x));
        }
    }
    return 0;
}