hdu1166(簡單線段樹應用，求區間和)

/*hdu1166(求區間和)*/#include <cstdio>#include <cstring>#define MAX 50000struct node{    int l,r,num;};node seg_tree[3*MAX];int n;void ori_tree(int n,int l,int r){    int m=(l+r)/2;    seg_tree[n].num=0;    seg_tree[n].l=l;    seg_tree[n].r=r;    if (l!=r){        if (l<=m)            ori_tree(2*n,l,m);        if (m+1<=r)            ori_tree(2*n+1,m+1,r);    }}int sum(int n,int l,int r){    int m=(seg_tree[n].l+seg_tree[n].r)/2;    if (seg_tree[n].l==l && seg_tree[n].r==r)        return seg_tree[n].num;    else if (r<=m)        return sum(n*2,l,r);    else if (l>m)        return sum(n*2+1,l,r);    else        return sum(n*2,l,m)+sum(n*2+1,m+1,r);}void insert(int n,int k,int s){    int m=(seg_tree[n].l+seg_tree[n].r)/2;    if (seg_tree[n].l==seg_tree[n].r)        seg_tree[n].num+=s;    else if (k<=m)    {            seg_tree[n].num+=s;            insert(n*2,k,s);    }    else    {        seg_tree[n].num+=s;        insert(n*2+1,k,s);    }}int main(){    int i,j,t,a,b,s;    char ord[101];    scanf("%d",&t);    for (j=1;j<=t;j++)    {        scanf("%d",&n);        ori_tree(1,1,n);        for (i=1;i<=n;i++)        {            scanf("%d",&s);            insert(1,i,s);        }        printf("Case %d:\n",j);        while (scanf("%s",ord) && strcmp(ord,"End")!=0)        {            scanf("%d%d",&a,&b);            if (strcmp(ord,"Add")==0)                insert(1,a,b);            else if (strcmp(ord,"Sub")==0)                insert(1,a,-b);            else                printf("%d\n",sum(1,a,b));        }    }    return 0;}