线段树模板

HDU-1166 单点更新

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <vector>
#include <cmath>
#include <set>

using namespace std;
typedef long long ll;
const int maxn = 50005;

int tree[maxn << 2], a[maxn];
int n;

void build(int rt, int l, int r) {
	if (l == r) {
		tree[rt] = a[l];
		return;
	}
	int mid = (l + r) >> 1;
	build(rt << 1, l, mid);
	build(rt << 1 | 1, mid + 1, r);
	tree[rt] = tree[rt << 1] + tree[rt << 1 | 1];
}

void update(int rt, int l, int r, int pos, int num) {
	if (l == r) {
		tree[rt] += num;
		return;
	}
	int mid = (l + r) >> 1;
	if (pos <= mid)update(rt << 1, l, mid, pos, num);
	else update(rt << 1 | 1, mid + 1, r, pos, num);

	tree[rt] = tree[rt << 1] + tree[rt << 1 | 1];
}

int query(int rt, int l, int r, int x, int y) {
	if (x <= l && y >= r) return tree[rt];

	int mid = (l + r) >> 1;
	if (y <= mid)return query(rt << 1, l, mid, x, y);
	else if (x > mid)return query(rt << 1 | 1, mid + 1, r, x, y);

	return query(rt << 1, l, mid, x, mid) + query(rt << 1 | 1, mid + 1, r, mid + 1, y);
}
int t;
int main() {
	ios::sync_with_stdio(false);
	int cas = 1;
	cin >> t;
	while (t--) {

		cin >> n;
		for (int i = 1; i <= n; i++)
			cin >> a[i];

		build(1, 1, n);
		string op;
		cout << "Case " << cas++ << ":" << endl;
		while (cin >> op && op[0] != 'E') {

			int a, b;
			cin >> a >> b;
			if (op[0] == 'Q') {
				cout << query(1, 1, n, a, b) << endl;
			}

			else if (op[0] == 'A') {
				update(1, 1, n, a, b);
			}

			else if (op[0] == 'S') {
				update(1, 1, n, a, -b);
			}
		}
	}
	return 0;
}

POJ-3468 区间更新

#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <vector>
#include <cmath>
#include <set>

using namespace std;
typedef long long ll;
const ll maxn=100005;
ll tree[maxn<<2];
ll a[maxn];
ll add[maxn<<2];
ll n,m;
void build(ll rt, ll l, ll r) {
    add[rt]=0;
    if(l==r) {
        tree[rt]=a[l];
        return  ;
    }
    ll mid=(l+r)>>1;
    build(rt<<1, l, mid);
    build(rt<<1|1, mid + 1, r);
    tree[rt]=tree[rt<<1]+tree[rt<<1|1];
}

void push_down(ll rt, ll m) {
    if(add[rt]) {
        add[rt<<1]+=add[rt];
        add[rt<<1|1]+=add[rt];

        tree[rt<<1]+=add[rt]*(m-(m>>1));
        tree[rt<<1|1]+=add[rt]*(m>>1);

        add[rt]=0;
    }
}

void update(ll rt, ll l, ll r, ll x, ll y, ll num) {
    if(x<=l&&y>=r) {
        add[rt]+=num;
        tree[rt]+=num*(r-l+1);
        return ;
    }
    push_down(rt,r-l+1);
    ll mid=(l+r)>>1;
    if(y<=mid)update(rt<<1,l,mid,x,y,num);
    else if(x>mid)update(rt<<1|1,mid+1,r,x,y,num);
    else {
        update(rt<<1,l,mid,x,mid,num);
        update(rt<<1|1,mid+1,r,mid+1,y,num);
    }
    tree[rt]=tree[rt<<1]+tree[rt<<1|1];
}

ll query(ll rt,ll l,ll r,ll x,ll y) {
    if(x<=l&&y>=r) return tree[rt];

    push_down(rt,r-l+1);
    ll mid=(l+r)>>1;
    if(y<=mid)return query(rt<<1,l,mid,x,y);

    else if(x>mid)return query(rt<<1|1,mid+1,r,x,y);

    return query(rt<<1,l,mid,x,y)+query(rt<<1|1,mid+1,r,x,y);
}

int main () {
    ios::sync_with_stdio(false);
    cin>>n>>m;
    for(ll i=1;i<=n;i++)
        cin>>a[i];
    build(1,1,n);
    for(ll i=0;i<m;i++) {
        char c;
        ll d1,d2;
        cin>>c>>d1>>d2;
        if(c=='Q') cout<<query(1,1,n,d1,d2)<<endl;
        else if(c=='C') {
            ll d3;
            cin>>d3;
            update(1,1,n,d1,d2,d3);
        }
    }
    return 0;
}