Problem:
Range Sum Query

Write a program which manipulates a sequence A = {a1, a2, . . . , an} with the following operations:

add(i, x): add x to ai.

getSum(s, t): print the sum of as, as+1,...,at.

Note that the initial values of ai (i = 1, 2, . . . , n) are 0.

Input

n q
com1 x1 y1
com2 x2 y2
...
comq xq yq

In the first line, n (the number of elements in A) and q (the number of queries) are given. Then, q queries are given where com represents the type of queries. '0' denotes add(xi, yi) and '1' denotes getSum(xi, yi).

Output

For each getSum operation, print the sum in a line.

Constraints

1 ≤ n ≤ 100000

1 ≤ q ≤ 100000

If comi is 0, then 1 ≤ xi ≤ n, 0 ≤ yi ≤ 1000.

If comi is 1, then 1 ≤ xi ≤ n, 1 ≤ yi ≤ n.

Sample Input 1

3 5
0 1 1
0 2 2
0 3 3
1 1 2
1 2 2

Sample Output 1

3
2

Solution in Ruby (judge verdict: Wrong Answer)

# range_sum_query
# 
# 
s=STDIN.gets.split
n = s[0].to_i
q = s[1].to_i

ar  = Array.new(100001,0)
ar2 = Array.new(1001  ,0)

1.upto(q) {
s=STDIN.gets.split
com = s[0].to_i
x   = s[1].to_i
y   = s[2].to_i
#printf(":%d %d %d\n",com,x,y)
if(com==0)
  x1=x/100
  diff = y - ar[x]
  ar[x]=y
  ar2[x1] += diff
elsif (com==1)
  x1=x/100
  y1=y/100
  ans_=0
  if(x1==y1 || x1+1==y1)
    x.upto(y){|i|
      ans_ += ar[i]
    }
  else
    if (x % 100) > 0 then
      x.upto(x1*100+99){|i| ans_ += ar[i]   }
      (x1+1).upto(y1-1){|i| ans_ += ar2[i]  }
    else
      x1.upto(y1-1){|i|     ans_ += ar2[i]  }
    end
    (y1*100).upto(y){|i| ans_ += ar[i]    } 
  end
  puts ans_
end
}