1 10 1 2 3 4 5 6 7 8 9 10 Query 1 3 Add 3 6 Query 2 7 Sub 10 2 Add 6 3 Query 3 10 End
Case 1: 6 33 59
学习下线段树。这题是更新点询问区间
代码：
#include <stdio.h>
#include <string.h>
const int N = 50005;
int t, n, num;
struct Tree {
int l, r, value;
}st[3 * N];
void build(int l, int r, int id) {
if (l != r) {
int mid = (l + r) / 2;
build(l, mid, 2 * id);
build(mid + 1, r, 2 * id + 1);
}
st[id].l = l; st[id].r = r; st[id].value = 0;
}
void Insert(int l, int r, int value, int id) {
if (st[id].l != st[id].r) {
int mid = (st[id].l + st[id].r) / 2;
if (l <= mid && r > mid) {Insert(l, mid, value, 2 * id); Insert(mid + 1, r, value, 2 * id + 1);}
else if (l <= mid && r <= mid) {Insert(l, r, value, 2 * id);}
else {Insert(l, r, value, 2 * id + 1);}
}
st[id].value += value;
}
int Query(int l, int r, int id) {
if (l == st[id].l && r == st[id].r)
return st[id].value;
int mid = (st[id].l + st[id].r) / 2;
if (l <= mid && r > mid) {return Query(l, mid, 2 * id) + Query(mid + 1, r, 2 * id + 1);}
else if (l <= mid && r <= mid) {return Query(l, r, 2 * id);}
else {return Query(l, r, 2 * id + 1);}
}
void init() {
scanf("%d", &n);
build(1, n, 1);
for (int i = 1; i <= n; i++) {
scanf("%d", &num);
Insert(i, i, num, 1);
}
}
void solve() {
char s[10];
int a, b;
while (~scanf("%s", &s) && s[0] != ‘E‘) {
scanf("%d%d", &a, &b);
if (s[0] == ‘Q‘) printf("%d\n", Query(a, b, 1));
else if (s[0] == ‘A‘) Insert(a, a, b, 1);
else Insert(a, a, -b, 1);
}
}
int main() {
int cas = 0;
scanf("%d", &t);
while (t--) {
init();
printf("Case %d:\n", ++cas);
solve();
}
return 0;
}
原文：http://blog.csdn.net/accelerator_/article/details/18736729