Submission #1551971

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Source Code Expand

#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>

using namespace std;

const int N = 2e5 + 500;
const int MOD = 1e9 + 7;
const int INF = 0x3f3f3f3f;

typedef pair < int ,int > pii;
typedef long long int llint;

vector < int > sazv;
vector < pii > vl;

int l[N],r[N],fen[2 * N],dp[N],n;

void add(int i,int x){
    for(;i<N;i+=i&-i){
        fen[i] = max(fen[i],x);
    }
}

int query(int i){
    int ret = 0;
    for(;i>0;i-=i&-i)
        ret = max(ret,fen[i]);
    return ret;
}

void sazimanje(){
    for(int i = 1;i<=vl.size();i++){
        sazv.push_back(vl[i].second);
    }
    sort(sazv.begin(),sazv.end());
    sazv.erase(unique(sazv.begin(),sazv.end()),sazv.end());

    for(int i = 1;i<=vl.size();i++){
        vl[i].second = lower_bound(sazv.begin(),sazv.end(),vl[i].second) - sazv.begin() + 1;
    }
}

void nadilr(){
    for(int i = 0;i<2*N;i++) fen[i] = 0;
    for(int i = 1;i<vl.size();i++){
        add(N - vl[i].second , N - i);
        l[i] = min(N - query(N - vl[i].second), (int)vl.size() - 1 );
    }
    for(int i = 0;i<2*N;i++) fen[i] = 0;
    for(int i = vl.size() - 1;i>=1;i--){
        add(vl[i].second , i);
        r[i] = query(vl[i].second);
    }
    for(int i = 0;i<2*N;i++) fen[i] = 0;
    for(int i = 1;i<vl.size() ;i++){
        add(r[i] ,l[i] );
    }
}

int din(){
    dp[0] = 1;
    for(int i = 1;i<vl.size();i++){
        int lim = query(i - 1);
        dp[i] = 2 * dp[i - 1] % MOD;
        if(lim) dp[i] -= dp[lim-1];
        if(dp[i] < 0) dp[i] += MOD;
    }
    int finlim = query(vl.size());
    int sol = dp[vl.size() - 1] - dp[finlim - 1];
    if(sol < 0) sol += MOD;
    return sol;
}

int main(){
    scanf("%d",&n);
    for(int i = 0;i<n;i++){
        int x,y;
        scanf("%d%d",&x,&y);
        vl.push_back(make_pair(x,y));
    }
    vl.push_back(make_pair(0,0));
    sort(vl.begin(),vl.end());
    sazimanje();
    nadilr();
    printf("%d\n",din());
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:77:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
                   ^
./Main.cpp:80:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&x,&y);
                            ^

Judge Result