pku3468 A Simple Problem with Integers

http://poj.org/problem?id=3468

线段树，成段更新

注意long long

  1 #include <stdio.h>
  2 
  3 #define lson l, m, root<<1
  4 #define rson m+1, r, root<<1|1
  5 #define N 100100
  6 
  7 long long sum[N<<2], add[N<<2];
  8 
  9 void push_up(int root)
 10 {
 11     sum[root] = sum[root<<1] + sum[root<<1|1];
 12 }
 13 
 14 void push_down(int root, int len)
 15 {
 16     if(add[root])
 17     {
 18         add[root<<1] += add[root];
 19         add[root<<1|1] += add[root];
 20         sum[root<<1] += add[root] * (len - (len>>1));
 21         sum[root<<1|1] += add[root] * (len>>1);
 22         add[root] = 0;
 23     }
 24 }
 25 
 26 void build(int l, int r, int root)
 27 {
 28     int m;
 29     add[root] = 0;
 30     if(l == r)
 31     {
 32         scanf("%lld", sum+root);
 33         return;
 34     }
 35     m = (l + r) >> 1;
 36     build(lson);
 37     build(rson);
 38     push_up(root);
 39 }
 40 
 41 void update(int L, int R, int x, int l, int r, int root)
 42 {
 43     int m;
 44     if(L <= l && r <= R)
 45     {
 46         add[root] += x;
 47         sum[root] += (r-l+1)*(long long)x;
 48         return;
 49     }
 50     push_down(root, r-l+1);
 51     m = (l + r) >> 1;
 52     if(L <= m)
 53     {
 54         update(L, R, x, lson);
 55     }
 56     if(m+1 <= R)
 57     {
 58         update(L, R, x, rson);
 59     }
 60     push_up(root);
 61 }
 62 
 63 long long query(int L, int R, int l, int r, int root)
 64 {
 65     int m;
 66     long long result;
 67     if(L <= l && r <= R)
 68     {
 69         return sum[root];
 70     }
 71     push_down(root, r-l+1);
 72     m = (l + r) >> 1;
 73     result = 0;
 74     if(L <= m)
 75     {
 76         result += query(L, R, lson);
 77     }
 78     if(m+1 <= R)
 79     {
 80         result += query(L, R, rson);
 81     }
 82     return result;
 83 }
 84 
 85 int main()
 86 {
 87     int n, q, a, b, c;
 88     char c1;
 89     scanf("%d%d", &n, &q);
 90     build(1, n, 1);
 91     getchar();
 92     while(q-- && scanf("%c%d%d%*c", &c1, &a, &b))
 93     {
 94         if(c1 == 'C')
 95         {
 96             scanf("%d%*c", &c);
 97             update(a, b, c, 1, n, 1);
 98             continue;
 99         }
100         printf("%lld\n", query(a, b, 1, n, 1));
101     }
102     return 0;
103 }

 

posted @ 2013-02-27 16:16  Yuan1991  阅读(133)  评论(0)  编辑  收藏  举报