【HDOJ】1166 敌兵布阵

线段树。

 #include <stdio.h>

 #define maxn 55555

 int sums[maxn<<];

 void PushUP(int rt) {
     sums[rt] = sums[rt<<] + sums[rt<<|];
 }

 void build(int l, int r, int rt) {
     int m;
     if (l == r) {
         scanf("%d", &sums[rt]);
         return ;
     }
     m = (l+r)>>;
     build(l, m, rt<<);
     build(m+, r, rt<<|);
     PushUP(rt);
 }

 void update(int des, int delta, int l, int r, int rt) {
     int m;
     if (l == r) {
         sums[rt] += delta;
         return ;
     }
     m = (l+r)>>;
     if (des <= m)
         update(des, delta, l, m, rt<<);
     else
         update(des, delta, m+, r, rt<<|);
     PushUP(rt);
 }

 int query(int ll, int rr, int l, int r, int rt) {
     int m, val = ;
     if (ll<=l && rr>=r)
         return sums[rt];

     m = (l+r)>>;
     if (ll <= m)
         val += query(ll, rr, l, m, rt<<);
     if (m < rr)
         val += query(ll, rr, m+, r, rt<<|);

     return val;
 }

 int main() {
     int case_n, n;
     char cmd[];
     int i, j, k;

     scanf("%d", &case_n);

     for (k=; k<=case_n; ++k) {
         scanf("%d", &n);
         build(, n, );
         printf("Case %d:\n", k);
         while () {
             scanf("%*c%s", cmd);
             if (cmd[] == 'E')
                 break;
             scanf("%d %d", &i, &j);
             if (cmd[] == 'Q')
                 printf("%d\n", query(i,j,,n,));
             else if (cmd[] == 'A')
                 update(i, j, , n, );
             else
                 update(i, -j, , n, );
         }
     }

     return ;
 }