CF978C Letters前缀和+二分查找/几房几号

Posted 2020-11-10 Roni

【链接】：CF978C
【分析】：在前缀和数组种二分找到>=询问数的位置，根据位置就好操作了
【代码】：

#include<bits/stdc++.h>
using namespace std;
const int  INF =  0x3f3f3f3f;
#define ll long long
#define ms(a,b) memset(a,b,sizeof(a))
#define rep(i,a,b) for(int i=(a); i<=(b); i++)
const int N = 2*1e5+5;
ll a[N],b[N],sum[N];
int main()
{
    int n,m;
    cin>>n>>m;
    memset(sum,0,sizeof(sum));
    rep(i,1,n) cin>>a[i], sum[i]=sum[i-1]+a[i];
    rep(i,1,m) cin>>b[i];
    rep(i,1,m)
    {
        if(b[i]<=a[1])
            printf("%d %lld\n",1,b[i]);
        else
        {
            ll j = lower_bound(sum,sum+n,b[i])-sum;
            printf("%lld %lld\n",j,b[i]-sum[j-1]);
        }
    }
}