递推 Codeforces Round #186 (Div. 2) B. Ilya and Queries

 

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/*
    递推：用cnt记录前缀值，查询区间时，两个区间相减 
*/
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <cstring>
using namespace std;

const int MAXN = 1e5 + 10;
const int INF = 0x3f3f3f3f;
char s[MAXN];
int cnt[MAXN];

int main(void)      //Codeforces Round #186 (Div. 2) B. Ilya and Queries
{
    scanf ("%s", s + 1);
    int len = strlen (s + 1);

    memset (cnt, 0, sizeof (cnt));
    for (int i=1; i<len; ++i)
    {
        cnt[i] = cnt[i-1] + (s[i] == s[i+1] ? 1 : 0);
//        printf ("%d ", cnt[i]);
    }
    cnt[len] = cnt[len-1];

    int m;    scanf ("%d", &m);
    while (m--)
    {
        int l, r;    scanf ("%d%d", &l, &r);
        printf ("%d\n", cnt[r-1] - cnt[l-1]);
    }

    return 0;
}