POJ 3468 A Simple Problem with Integers

来源：互联网发布：nginx web服务器配置编辑：程序博客网时间：2024/06/10 23:59

区间修改，区间求和。用线段树维护区间和，区间修改打lazy标记。

#include <iostream>#include <cstring>#include <cstdio>#include <algorithm>#define lson l,m,rt<<1#define rson m+1,r,rt<<1|1const int maxn = 111111;using namespace std;long long lazy[maxn<<2],sum[maxn<<2];void pushup(int rt){    sum[rt] = sum[rt<<1] + sum[rt<<1|1];}void pushdown(int rt,int m){    if(lazy[rt])    {        lazy[rt<<1] += lazy[rt];        lazy[rt<<1|1] += lazy[rt];        sum[rt<<1] += (m-(m>>1))*lazy[rt];        sum[rt<<1|1] += (m>>1)*lazy[rt];        lazy[rt] = 0;    }}void build(int l ,int r,int rt){    lazy[rt] = 0;    if(l == r)    {        scanf("%I64d",&sum[rt]);        return;    }    int m = (r+l)>>1;    build(lson);    build(rson);    pushup(rt);}void update(int L,int R,int c,int l ,int r ,int rt){    if(L <= l && r <= R)    {        lazy[rt] += c;        sum[rt] += (long long)c*(r-l+1);        return ;    }    pushdown(rt,r-l+1);    int m = (r+l)>>1;    if(L <= m) update(L,R,c,lson);    if(R > m) update(L,R,c,rson);    pushup(rt);}long long query(int L,int R,int l ,int r ,int rt){    if(L <= l && r <= R)    {        return sum[rt];    }    pushdown(rt,r-l+1);    long long res = 0;    int m = (l+r)>>1;    if(L <= m) res +=query(L,R,lson);    if(R > m) res +=query(L,R,rson);    return res;}int main(){    int n , q;    scanf("%d%d",&n,&q);    build(1,n,1);    while(q--)    {        char op[2];        int a,b,c;        scanf("%s",op);        if(op[0] == 'Q')        {            scanf("%d%d",&a,&b);            printf("%I64d\n",query(a,b,1,n,1));        }        else if(op[0] == 'C')        {            scanf("%d%d%d",&a,&b,&c);            update(a,b,c,1,n,1);        }    }    return 0;}

0 0