Submission #88486

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Source Code Expand

/*  
Alfonso2 Peterssen  
9 - 5 - 2008  
IOI 2004 Day2 Task "Empodia"  
*/   
#include <cstdio>   
#include <algorithm>   
#include <stack>   
   
using namespace std;   
   
const int MAXN = 1100000;   
   
typedef pair< int, int > par;   
   
int N, E, cant;   
int i, j, a, b;   
int seq[MAXN];   
int ans[MAXN];   
int last[MAXN];   
int next[MAXN];   
int empodio[MAXN];   
bool deleted[MAXN];   
stack< int > S;   
par vals[MAXN];   
par events[MAXN];   
   
int main() {   
   
    scanf( "%d", &N );   
    for ( i = 0; i < N; i++ )   
        scanf( "%d", &seq[i] );   
   
    for ( i = 0; i < N; last[i] = j, i++ )   
        for ( j = i - 1; j >= 0 && seq[j] < seq[i]; j = last[j] );   
   
    for ( i = N - 1; i >= 0; next[i] = j, i-- )   
        for ( j = i + 1; j < N && seq[j] > seq[i]; j = next[j] );   
   
    for ( i = 0; i < N; i++ )   
        vals[i] = par( seq[i] - i, i );   
   
    /* Find all empodios */   
    sort( vals, vals + N );   
    for ( i = 0; i < N; i++ ) {   
        a = vals[i].second;   
        for ( j = i + 1; j < N &&   
              vals[i].first == vals[j].first; j++ ) {   
            b = vals[j].second;   
            if ( next[a] <= b ) break;   
            if ( last[b] < a && next[a] > b ) {   
                empodio[b] = a;   
                events[E++] = par( a, +(i+1) );   
                events[E++] = par( b, -(i+1) );   
                break;   
            }   
        }   
    }   
   
    /* Find inner intervals */   
    sort( events, events + E );   
    for ( i = 0; i < E; i++ ) {   
        int id = events[i].second;   
        if ( id > 0 ) S.push( abs(id) );   
        if ( id < 0 && !deleted[ abs(id) ] ) {   
            while ( !S.empty() ) {   
                deleted[ S.top() ] = true;   
                S.pop();   
            }   
            ans[cant++] = events[i].first;   
        }   
    }   
   
    printf( "%d\n", cant );   
    for ( i = 0; i < cant; i++ )   
        printf( "%d %d\n", empodio[ ans[i] ] + 1, ans[i] + 1 );   
   
    return 0;   
}   

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:31:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
./Main.cpp:33:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]

Judge Result