线段树点修改

 1 #include <cstdio>
 2 #include <iostream>
 3 #include <algorithm>
 4 #include <cstring>
 5 #include <cmath>
 6 using namespace std;
 7 const int maxn = 1000000 + 10;
 8 const int maxn3 = maxn * 3;
 9 const int INF = -1u >> 1;
10 int A[maxn], Minv[maxn3], Maxv[maxn3], Sumv[maxn3], x, v, ql, qr, _min, _max, _sum;
11 int n, Q, tt = 0;
12 char tp;
13 void fresh(int o, int lc, int rc){
14     Minv[o] = min(Minv[lc], Minv[rc]);
15     Maxv[o] = max(Maxv[lc], Maxv[rc]);
16     Sumv[o] = Sumv[lc] + Sumv[rc];
17     return ;
18 }
19 void build(int o, int L, int R){
20     if(L == R) Sumv[o] = Minv[o] = Maxv[o] = A[L];
21     else{
22         int M = L + R >> 1, lc = o << 1, rc = lc | 1;
23         build(lc, L, M);
24         build(rc, M + 1, R);
25         fresh(o, lc, rc);
26     }
27     return ;
28 }
29 void update(int o, int L, int R){
30     if(L == R) Minv[o] = Maxv[o] = Sumv[o] = v;
31     else{
32         int M = L + R >> 1, lc = o << 1, rc = lc | 1;
33         if(x <= M) update(lc, L, M);
34         else update(rc, M + 1, R);
35         fresh(o, lc, rc);
36     }
37     return ;
38 }
39 void query(int o, int L, int R){
40     if(ql <= L && R <= qr){
41         _min = min(_min, Minv[o]);
42         _max = max(_max, Maxv[o]);
43         _sum = _sum + Sumv[o];
44     }
45     else{
46         int M = L + R >> 1, lc = o << 1, rc = lc | 1;
47         if(ql <= M) query(lc, L, M);
48         if(qr > M) query(rc, M + 1, R);
49     }
50     return ;
51 }
52 void read(int &x){
53     x = 0; int sig = 1; char ch = getchar();
54     while(!isdigit(ch)) { if(ch == ‘-‘) sig = -1; ch = getchar(); }
55     while(isdigit(ch)) x = 10 * x + ch - ‘0‘, ch = getchar();
56     x *= sig; return ;
57 }
58 void read(char& x){
59     x = getchar();
60     while(!isalpha(x)) x = getchar();
61     return ;
62 }
63 void init(){
64     read(n);
65     for(int i = 1; i <= n; i ++) read(A[i]);
66     build(1, 1, n);
67     read(Q);
68     return ;
69 }
70 void work(){
71     while(Q--){
72         read(tp); read(ql); read(qr);
73         if(tp == ‘Q‘){
74             _sum = 0; _max = -INF; _min = INF;
75             query(1, 1, n);
76             printf("MaxNum: %d, MinNum: %d, Sum: %d\n", _max, _min, _sum);
77         }
78         else{
79             x = ql; v = qr;
80             update(1, 1, n);
81         }
82     }
83     return ;
84 }
85 void print(){
86 
87     return ;
88 }
89 int main(){
90     init();
91     work();
92     print();
93     return 0;
94 }