codeforces 313B
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), that si = 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
题目的意思是输入一行只有#和.的字符串,然后输入m对数(l,r)计算r-l中最大连续出现的字符有几个。
首先先计算字符串最大连续的字符有几个,记为数组dp,如果与前一个字符相同就加一,不同就等于上一次的dp。
#define _CRT_SECURE_NO_WARNINGS #include<stdio.h> #include<string.h> #define N 100005 char s[N]; int dp[N]; int main() { int l, r, i, m, n; scanf("%s", s); n = strlen(s); memset(dp, 0, n); scanf("%d", &m); for (i = 1;i < n;i++) { dp[i] = dp[i - 1]; if (s[i] == s[i - 1]) dp[i]++; } for (i = 0;i < m;i++) { scanf("%d%d", &l, &r); printf("%d\n", dp[r - 1] - dp[l - 1]); } return 0; }