学步园

#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxn = 100010;
int n, m;
bool vis[maxn];
int c[maxn], a[maxn], pos[maxn];
struct Query {
    int l, r, id;
    bool operator <(const Query &t) const {
        return l < t.l;
    }
} q[maxn];
int ans[maxn];
inline int sum(int x) {
    int s = 0;
    while (x > 0) {
        s += c[x];
        x -= x & -x;
    }
    return s;
}
inline void add(int x, int v) {
    while (x <= n) {
        c[x] += v;
        x += x & -x;
    }
}
int main() {
    int i, j, cas, l, r;
    scanf("%d", &cas);
    while (cas--) {
        scanf("%d%d", &n, &m);
        for (i = 1; i <= n; i++) {
            vis[i] = 0;
            scanf("%d", &a[i]);
            pos[a[i]] = i;
            c[i] = 0;
        }
        for (i = 0; i < m; i++) {
            scanf("%d%d", &q[i].l, &q[i].r);
            q[i].id = i;
        }
        l = 1;
        for(i = 1; i <= n; i++) {
              add(i, 1 - vis[a[i] - 1] - vis[a[i] + 1]);
                vis[a[i]] = 1;
        }
        sort(q, q + m);
        for (i = 0; i < m; i++) {
            while (l < q[i].l) {
                add(l, -1);
                vis[a[l]] = 0;
                if (vis[a[l] - 1])
                    add(pos[a[l] - 1], 1);
                if (vis[a[l] + 1])
                    add(pos[a[l] + 1], 1);
                l++;
            }

            ans[q[i].id] = sum(q[i].r);
        }
        for (i = 0; i < m; i++)
            printf("%d\n", ans[i]);
    }
    return 0;
}
/*

 */