Ilya the Lion wants to help all his friends with passing exams. They need to solve the following problem to pass the IT exam.
You've got string s = s1s2... sn (n is the length of the string), consisting only of characters "." and "#" and m queries. Each query is described by a pair of integers li, ri (1 ≤ li < ri ≤ n). The answer to the query li, ri is the number of such integers i (li ≤ i < ri), thatsi = si + 1.
Ilya the Lion wants to help his friends but is there anyone to help him? Help Ilya, solve the problem.
The first line contains string s of length n (2 ≤ n ≤ 105). It is guaranteed that the given string only consists of characters "." and "#".
The next line contains integer m (1 ≤ m ≤ 105) — the number of queries. Each of the next m lines contains the description of the corresponding query. The i-th line contains integers li, ri (1 ≤ li < ri ≤ n).
Print m integers — the answers to the queries in the order in which they are given in the input.
......
4
3 4
2 3
1 6
2 6
1
1
5
4
#..###
5
1 3
5 6
1 5
3 6
3 4
1
1
2
2
0
题意:找出给定区间内相邻字符的个数。水题,不多解释。
#include<iostream> #include<string> using namespace std; int main() { string s; while (cin >> s) { int n, a[100005] = { 0 }; for (int i = 1; i < s.length(); i++) { if (s[i-1] == s[i]) a[i] = a[i - 1] + 1; else a[i] = a[i - 1]; } cin >> n; while (n--) { int x, y; cin >> x >> y; cout << a[y - 1] - a[x - 1] << endl;; } } return 0; }