分块入门

分好块就能写。。

#include 
    
     #define INF 0x3f3f3f3f#define full(a, b) memset(a, b, sizeof a)using namespace std;typedef long long ll;inline int lowbit(int x){ return x & (-x); }inline int read(){    int X = 0, w = 0; char ch = 0;    while(!isdigit(ch)) { w |= ch == '-'; ch = getchar(); }    while(isdigit(ch)) X = (X << 3) + (X << 1) + (ch ^ 48), ch = getchar();    return w ? -X : X;}inline int gcd(int a, int b){ return b ? gcd(b, a % b) : a; }inline int lcm(int a, int b){ return a / gcd(a, b) * b; }template
     
      inline T max(T x, T y, T z){ return max(max(x, y), z); }template
      
       inline T min(T x, T y, T z){ return min(min(x, y), z); }template
       
        inline A fpow(A x, B p, C lyd){    A ans = 1;    for(; p; p >>= 1, x = 1LL * x * x % lyd)if(p & 1)ans = 1LL * x * ans % lyd;    return ans;}const int N = 50005;ll a[N], add[N];int lt[N], rt[N], pos[N], n, t;void modify(int l, int r, ll d){    int p = pos[l], q = pos[r];    if(p == q){        for(int i = l; i <= r; i ++) a[i] += d;    }    else{        for(int i = p + 1; i <= q - 1; i ++) add[i] += d;        for(int i = l; i <= rt[p]; i ++) a[i] += d;        for(int i = lt[q]; i <= r; i ++) a[i] += d;    }}ll query(int k){    return a[k] + add[pos[k]];}int main(){    ios::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);    cin >> n;    for(int i = 1; i <= n; i ++) cin >> a[i];    t = (int)sqrt(n);    for(int i = 1; i <= t; i ++){        lt[i] = (i - 1) * t + 1;        rt[i] = i * t;    }    if(rt[t] < n) t ++, lt[t] = rt[t - 1] + 1, rt[t] = n;    for(int i = 1; i <= t; i ++){        for(int j = lt[i]; j <= rt[i]; j ++){            pos[j] = i;        }    }    for(int i = 1; i <= n; i ++){        int opt, l, r; ll c;        cin >> opt >> l >> r >> c;        if(!opt) modify(l, r, c);        else cout << query(r) << endl;    }    return 0;}