unique函数使用过程

1. 不仅要复制 ，而且要递增

题目注意事项

1. 进行增加数字的时候，需要注意下标可能是重合的部分

#include <iostream>
#include <cstdio>
#include <algorithm>

using namespace std;

typedef pair<int, int> pII;

vector<int> alls;
vector<pII> add, query;

const int N = 300010;


int n, m;
int a[N], s[N];

int find(int x)
{
    int l = 0, r = alls.size();
    while(l < r)
    {
        int mid = l + r >> 1;
        if(alls[mid] >= x) r = mid;
        else l = mid + 1;
    }
    return l;
}

vector<int>::iterator unique( vector<int>::iterator &fi, vector<int>::iterator &se)
{
    vector<int>::iterator it = fi;
    fi++;
    for(; fi != se; fi++)
        if((*fi) != *(it))
        {
            *it = *fi;
            it++;
        }
    return ++it;
}

int main()
{
    scanf("%d%d", &n, &m);
    for(int i = 0; i < n; i ++)
    {
        int x, y; scanf("%d%d", &x, &y);
        add.push_back({x,y});
        alls.push_back(x);
    }
    while(m --)
    {
        int l, r;
        cin >> l >> r;
        alls.push_back(r);
        alls.push_back(l);
        query.push_back({l,r});
    }
    sort(alls.begin(), alls.end());
    alls.erase(unique(alls.begin(), alls.end()), alls.end());
    for(auto c : add)
    {
        int x = find(c.first);
        x++;
        a[x] += c.second; //可能之前是有相同的数值，所以需要+=;
    }
    for(int i = 1, len = alls.size(); i <= len; i ++)
    {
        s[i] = s[i - 1] + a[i];
    }
    for(auto c : query)
    {
        int l = find(c.first), r = find(c.second);
        r++, l++;
        cout << s[r] - s[l - 1] << endl;
    }

    return 0;
}