HDU 1166(线段树；树状数组)

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

int a[50009];

int lowbit(int n)
{
return n&-n;
}

int sum(int end)
{
int s = 0;
while (end > 0)
{
s += a[end];
end -= lowbit(end);
}
return s;
}

void plus(int pos, int num, int up)
{
while (pos <= up)
{
a[pos] += num;
pos += lowbit(pos);
}
}

int main()
{
int T, N, i, n, m, t = 0;
char s[20];
scanf("%d", &T);
while (T--)
{
printf("Case %d:\n", ++t);
scanf("%d", &N);
memset(a+1, 0, sizeof(int) * N);
for (i = 1; i <= N; ++i)
{
scanf("%d", &n);
plus(i, n, N);
}
while (scanf("%s", s), s[0] != 'E')
{
scanf("%d%d", &n, &m);
if (s[0] == 'Q')
printf("%d\n", sum(m) - sum(n-1));
else if (s[0] == 'A')
{
plus(n, m, N);
}
else plus(n, -m, N);
}
}
}

#include <cstdio>
#include <cstring>

const int maxn = 50009;

int sum[maxn<<2];

void pushUP(int rt)
{
sum[rt] = sum[rt<<1] + sum[rt<<1|1];
}

void build(int l, int r, int rt)
{
if (l == r)
{
scanf("%d", sum+rt);
return;
}
int m = (l+r) >> 1;
build(l, m, rt<<1);
build(m+1, r, rt<<1|1);
pushUP(rt);
}

void update(int p, int add, int l, int r, int rt)
{
if (l == r)
{
sum[rt] += add;
return;
}
int m = (l+r) >> 1;
if (p <= m) update(p, add, l, m, rt<<1);
else update(p, add, m+1, r, rt<<1|1);
pushUP(rt);
}

int query(int L, int R, int l, int r, int rt)
{
if (L <= l && r <= R)
return sum[rt];
int m = (l + r) >> 1;
int ret = 0;
if (L <= m) ret += query(L, R, l, m, rt<<1);
if (R > m) ret += query(L, R, m+1, r, rt<<1|1);
return ret;
}

int main()
{
int T, n;
scanf("%d", &T);
for (int cas = 1; cas <= T; ++cas)
{
printf("Case %d:\n", cas);
scanf("%d", &n);
build(1, n, 1);
char op[10];
while (scanf("%s", op))
{
if (op[0] == 'E') break;
int a, b;
scanf("%d%d", &a, &b);
if (op[0] == 'Q')
printf("%d\n", query(a, b, 1, n, 1));
else if (op[0] == 'S')
update(a, -b, 1, n, 1);
else update(a, b, 1, n, 1);
}
}
return 0;
}