【树状数组 区间更新区间查询】code

Link：http://codevs.cn/problem/1082/

#include<cstdio>#include<cstring>#include<algorithm>using namespace std;typedef long long LL;//c[i] = a[i]-a[i-1]//c2[i] = (i-1)*c[i]//树状数组维护c,c2//ans[1-n]: n*sigma(c,n) - sigma(c2,n)const int N = 200010;#define lowbit(i) (i&(-i))LL c[N],c2[N];LL n;void up(LL *r,LL x,LL val){    while(x<=n){        r[x] += val;        x += lowbit(x);    }}LL down(LL *r,LL x){    LL ans = 0;    while(x){        ans += r[x];        x -= lowbit(x);    }    return ans;}int main(){    LL q;    scanf("%lld",&n);    for(int i = 1; i <= n; i++){        LL f;        scanf("%lld",&f);        up(c,i,f); up(c,i+1,-f);        up(c2,i,f*(i-1)); up(c2,i+1,-f*(i));    }    scanf("%lld",&q);    while(q--){        int type;        scanf("%d",&type);        LL a,b,f;        if(type==1){            scanf("%lld%lld%lld",&a,&b,&f);            up(c,a,f); up(c,b+1,-f);            up(c2,a,f*(a-1)); up(c2,b+1,-f*b);        }        else{            scanf("%lld%lld",&a,&b);            LL l = (a-1)*down(c,a-1) - down(c2,a-1);            LL r = b*down(c,b) - down(c2,b);            printf("%lld\n",r-l);        }    }    return 0;}