线段树 ： hdu 1166 示例 [ 单点更新 ]

#include <iostream>#include <string>#include <cstring>#include <cstdlib>#include <cstdio>#include <cmath>#include <vector>#include <stack>#include <deque>#include <queue>#include <bitset>#include <list>#include <map>#include <set>#include <iterator>#include <algorithm>#include <functional>#include <utility>#include <sstream>#include <climits>#include <cassert>#define BUG puts("here!!!");#define mid(x) (x) >> 1using namespace std;const int N = 50005;struct Node {int a, b;int sum;}t[3*N];int SUM = 0;int r[N];void makeTree(int x, int y, int num) {t[num].a = x;t[num].b = y;if(x == y) t[num].sum = r[y];else {    int m = mid(x+y);makeTree(x, m, 2*num);makeTree(m+1, y, 2*num+1);t[num].sum = t[2*num].sum + t[2*num+1].sum;}}void add(int x, int ren, int num) {t[num].sum += ren;if(x == t[num].a && x == t[num].b) return;if(x <= mid(t[num].a + t[num].b)) {add(x, ren, 2*num);}else add(x, ren, 2*num+1);}void query(int x, int y, int num) {if(x <= t[num].a && t[num].b <= y) { // 找终止SUM += t[num].sum;}else {        int m = mid(t[num].a + t[num].b);        if(x <= m) query(x, y, 2*num);        if(y > m) query(x, y, 2*num+1);}}int main() {int e = 0, T, n;cin >> T;while(T--) {memset(r, 0, sizeof(r));memset(t, 0, sizeof(t));cout << "Case " << ++e << ':' << endl;cin >> n;for(int i = 1; i <= n; i++) {scanf("%d", r+i);}makeTree(1, n, 1);char str[10];int a, b;while(scanf("%s", str)) {if(str[0] == 'E') {break;}else if(str[0] == 'A') {scanf("%d%d", &a, &b);add(a, b, 1);}else if(str[0] == 'S') {scanf("%d%d", &a, &b);add(a, (-b), 1);}else if(str[0] == 'Q') {scanf("%d%d", &a, &b);SUM = 0;query(a, b, 1);printf("%d\n", SUM);}}}return 0;}