Educational Codeforces Round 3:D. Gadgets for dollars and pounds(二分答案+贪心)

#include"cstdio"
#include"queue"
#include"cmath"
#include"stack"
#include"iostream"
#include"algorithm"
#include"cstring"
#include"queue"
#include"vector"
#define ll long long

using namespace std;
const int MAXN = 200050;
const int INF = 0x3f3f3f3f;
ll n,m,k,s;
ll d[MAXN],p[MAXN],mind[MAXN],minp[MAXN];
int mindpos[MAXN],minppos[MAXN];
struct node{
    ll c,o;
    node(){}
    node(ll a,ll b):c(a),o(b){}
};

vector<node> dd,pp;

bool cmp(node a,node b){
    return a.c<b.c;
}

bool judge(ll x){
    ll tot=0,cnt=0;
    int i=0,j=0;
    while(cnt<k&&tot<=s){
        ll td=INF,tp=INF;
        if(i<dd.size()) td=mind[x]*dd[i].c;
        if(j<pp.size()) tp=minp[x]*pp[j].c;

        if(td<tp){
            tot+=td;
            i++;
        }
        else{
            tot+=tp;
            j++;
        }
        cnt++;
    }
    if(tot>s) return false;
    return true;
}

void display(ll ans){
    if(ans==-1) return ;
    ll cnt=1;
    int i=0,j=0;
    while(cnt<=k){
        ll td=INF,tp=INF;
        if(i<dd.size()) td=mind[ans]*dd[i].c;
        if(j<pp.size()) tp=minp[ans]*pp[j].c;

        if(td<tp)
            printf("%I64d %d\n",dd[i++].o,mindpos[ans]);
        else
            printf("%I64d %d\n",pp[j++].o,minppos[ans]);
        cnt++;
    }
}

int main(){
    //freopen("in.txt","r",stdin);
    scanf("%I64d%I64d%I64d%I64d",&n,&m,&k,&s);
    minp[0]=mind[0]=INF;
    for(int i=1;i<=n;i++) {
        scanf("%I64d",&d[i]);
        mind[i]=min(mind[i-1],d[i]);
        if(mind[i]!=mind[i-1]) mindpos[i]=i;
        else mindpos[i]=mindpos[i-1];
    }
    for(int i=1;i<=n;i++) {
        scanf("%I64d",&p[i]);
        minp[i]=min(minp[i-1],p[i]);
        if(minp[i]!=minp[i-1]) minppos[i]=i;
        else minppos[i]=minppos[i-1];
    }
    for(int i=1;i<=m;i++) {
        ll t,c;
        scanf("%I64d%I64d",&t,&c);
        if(t==1) {
            dd.push_back(node(c,i));
        }
        else pp.push_back(node(c,i));
    }
    sort(dd.begin(),dd.end(),cmp);
    sort(pp.begin(),pp.end(),cmp);
    //for(int i=1;i<=n;i++) cout<<mindpos[i]<<‘\t‘<<minppos[i]<<endl;

    ll low=1,high=n,mid,ans=-1;
    while(low<=high){
        mid=(low+high)>>1;
        if(judge(mid)){
            ans=mid;
            high=mid-1;
        }
        else low=mid+1;
    }
    printf("%I64d\n",ans);
    display(ans);
    return 0;
}