func_code_string: #include <bits/stdc++.h>   using namespace std;   bool cur1;   int A[100005];   void check_min(int &x, int y) {     if (x > y) x = y;   }   void check_max(int &x, int y) {     if (x < y) x = y;   }   struct node {     int sum;     int mx, L, R;     int mxL, ToL, mxR, ToR;     void Init(int d, int x) {       sum = d;       mx = d;       mxL = d;       mxR = d;       L = x, R = x, ToL = x, ToR = x;     }     node operator+(const node &_) const {       node res;       res.sum = sum + _.sum;       res.mx = max(mx, _.mx);       if (mx == res.mx)         res.L = L, res.R = R;       else         res.L = _.L, res.R = _.R;       if (mxR + _.mxL > res.mx) {         res.mx = mxR + _.mxL;         res.L = ToR;         res.R = _.ToL;       }       res.mxL = mxL;       res.ToL = ToL;       if (sum + _.mxL > res.mxL) {         res.mxL = sum + _.mxL;         res.ToL = _.ToL;       }       res.mxR = _.mxR;       res.ToR = _.ToR;       if (_.sum + mxR > res.mxR) {         res.mxR = _.sum + mxR;         res.ToR = ToR;       }       return res;     }     void Print() {       printf( sum=%d n , sum);       printf( res=%d [%d %d] n , mx, L, R);       printf( sumL=%d ToL=%d n , mxL, ToL);       printf( sumR=%d ToR=%d n , mxR, ToR);     }   };   struct Segment_tree {     struct tree_node {       int L, R;       node val1, val2;       bool Lazy;       void Reverse() {         Lazy = !Lazy;         swap(val1, val2);       }       tree_node operator+(const tree_node &_) const {         tree_node res;         res.L = L;         res.R = _.R;         res.val1 = val1 + _.val1;         res.val2 = val2 + _.val2;         return res;       }     } tree[100005 << 2];     int Pc[100005];     void Up(int p) {       tree[p].val1 = tree[p << 1].val1 + tree[p << 1 | 1].val1;       tree[p].val2 = tree[p << 1].val2 + tree[p << 1 | 1].val2;     }     void Down(int p) {       if (!tree[p].Lazy) return;       tree[p << 1].Reverse();       tree[p << 1 | 1].Reverse();       tree[p].Lazy = false;     }     void Build(int L, int R, int p) {       tree[p].L = L, tree[p].R = R;       tree[p].Lazy = false;       if (L == R) {         Pc[L] = p;         tree[p].val1.Init(A[L], L);         tree[p].val2.Init(-A[L], L);         return;       }       int mid = (L + R) >> 1;       Build(L, mid, p << 1);       Build(mid + 1, R, p << 1 | 1);       Up(p);     }     void Change(int L, int R, int p) {       if (L <= tree[p].L && tree[p].R <= R) {         tree[p].Reverse();         return;       }       Down(p);       int mid = (tree[p].L + tree[p].R) >> 1;       if (R <= mid)         Change(L, R, p << 1);       else if (L > mid)         Change(L, R, p << 1 | 1);       else         Change(L, mid, p << 1), Change(mid + 1, R, p << 1 | 1);       Up(p);     }     tree_node Query(int L, int R, int p) {       if (L <= tree[p].L && tree[p].R <= R) return tree[p];       Down(p);       int mid = (tree[p].L + tree[p].R) >> 1;       if (R <= mid)         return Query(L, R, p << 1);       else if (L > mid)         return Query(L, R, p << 1 | 1);       else         return Query(L, mid, p << 1) + Query(mid + 1, R, p << 1 | 1);     }     int STK[100005];     void Updata(int x) {       int p = Pc[x], top = 0;       while (p) {         STK[++top] = p;         p >>= 1;       }       for (int i = top; i >= 2; i--) Down(STK[i]);       tree[Pc[x]].val1.Init(A[x], x);       tree[Pc[x]].val2.Init(-A[x], x);       for (int i = 2; i <= top; i++) Up(STK[i]);     }   } ST;   int stk[100005][2];   bool cur2;   int main() {     int n, m;     scanf( %d , &n);     for (int i = 1; i <= n; i++) scanf( %d , &A[i]);     ST.Build(1, n, 1);     scanf( %d , &m);     while (m--) {       int op;       scanf( %d , &op);       if (op == 0) {         int x, d;         scanf( %d%d , &x, &d);         A[x] = d;         ST.Updata(x);       } else {         int L, R, K;         scanf( %d%d%d , &L, &R, &K);         int ans = 0, top = 0;         while (K--) {           node res = ST.Query(L, R, 1).val1;           if (res.mx < 0) break;           ans += res.mx;           ST.Change(res.L, res.R, 1);           top++;           stk[top][0] = res.L, stk[top][1] = res.R;         }         while (top) ST.Change(stk[top][0], stk[top][1], 1), top--;         printf( %d n , ans);       }     }     return 0;   }   