《树状数组》hdu acm 5.3.2 一维

#include<stdio.h>
#include<string.h>
int map[50005]; int n; int sum(int x) { int ret = 0,i; for (i = x;i > 0;i -= (i&-i)) {
		ret += map[i]; } return ret; } void add(int x, int y) { int i; for (i = x;i <=n;i += (i&-i)) {
		map[i] += y; } } int main() { int t, num,a,b,c,i,k; char str[25];
	k = 0;
	scanf("%d", &t); while (t--) {
		printf("Case %d:\n", ++k);
		memset(map, 0, sizeof(map));
		scanf("%d", &n); for (i = 1;i <= n;i++) {
			scanf("%d", &num);
			add(i, num); } while (scanf("%s", str) && strcmp(str, "End")!=0) {
			scanf("%d%d", &a, &b); if (strcmp(str, "Query")==0) {
				printf("%d\n", sum(b) - sum(a-1)); } else if (strcmp(str, "Add")==0) {
				add(a, b); } else {
				add(a,-b); } } } return 0; }