codeforces 551E. GukiZ and GukiZiana 分块

#include<bits/stdc++.h>
using namespace std;
#define pb(x) push_back(x)
#define ll long long
#define mk(x, y) make_pair(x, y)
#define lson l, m, rt<<1
#define mem(a) memset(a, 0, sizeof(a))
#define rson m+1, r, rt<<1|1
#define mem1(a) memset(a, -1, sizeof(a))
#define mem2(a) memset(a, 0x3f, sizeof(a))
#define rep(i, a, n) for(int i = a; i<n; i++)
#define ull unsigned long long
typedef pair<int, int> pll;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int mod = 1e9+7;
const int inf = 1061109567;
const int dir[][2] = { {-1, 0}, {1, 0}, {0, -1}, {0, 1} };
multiset <int> s[1000];
const int maxn = 5e5+5;
int a[maxn], N, add[1005], n;
void modify(int l, int r, int val) {
    for(int i = l; i<=r; i++) {
        if(i%N==0&&i+N-1<=r) {
            add[i/N] += val;
            if(add[i/N]>1e9)
                add[i/N] = 1e9+1;
            i+=N-1;
        } else {
            s[i/N].erase(s[i/N].find(a[i]));
            a[i]+=val;
            if(a[i]>1e9)
                a[i] = 1e9+1;
            s[i/N].insert(a[i]);
        }
    }
}
int query(int x) {
    int l = -1, r = -2;
    for(int i = 0; i<n; i++) {
        if(a[i] + add[i/N] == x) {
            l = i;
            break;
        }
        if(i%N==0&&i+N-1<n) {
            if(s[i/N].find(x-add[i/N])==s[i/N].end())
                i+=N-1;
        }
    }
    for(int i = n-1; i>=0; i--) {
        if(a[i] + add[i/N] == x) {
            r = i;
            break;
        }
        if((1+i)%N == 0) {
            if(s[i/N].find(x-add[i/N]) == s[i/N].end())
                i = i-N+1;
        }
    }
    return r-l;
}
int main()
{
    int m, cnt = 0;
    cin>>n>>m;
    N = sqrt(n*1.0);
    for(int i = 0; i<n; i++) {
        scanf("%d", &a[i]);
        if(i&&i%N==0)
            cnt++;
        s[cnt].insert(a[i]);
    }
    while(m--) {
        int sign, l, r, val;
        scanf("%d", &sign);
        if(sign == 1) {
            scanf("%d%d%d", &l, &r, &val);
            l--, r--;
            modify(l, r, val);
        } else {
            scanf("%d", &val);
            cout<<query(val)<<endl;
        }
    }
    return 0;
}