Submission #25136

#	Time	Username	Problem	Language	Result	Execution time	Memory
25136		zoomswk	Global Warming (NOI13_gw)	C++14	0 / 40	0 ms	1016 KiB

gw

#include <stdio.h>
#include <algorithm>
#include <vector>
#include <map>
using namespace std;

int h[1000005];
int tmp[1000005];
map<int, int> mp;
vector<int> vt[1000005];
int par[1000005];

int findpar(int x){
    if(par[x] != x) par[x] = findpar(par[x]);
    return par[x];
}

int main(){
    int n;
    scanf("%d", &n);
    for(int i=0; i<n; i++){
        scanf("%d", &h[i]);
        tmp[i] = h[i];
    }
    sort(tmp, tmp+n);
    for(int i=0; i<n; i++) mp[tmp[i]] = i;
    for(int i=0; i<n; i++) vt[mp[h[i]]].push_back(i);
    int res = 0, cur = 0;
    for(int i=0; i<=n; i++) par[i] = n;
    for(int i=n-1; i>=0; i--){
        cur += vt[i].size();
        for(int j=0; j<vt[i].size(); j++){
            par[vt[i][j]] = vt[i][j];
        }
        for(int j=0; j<vt[i].size(); j++){
            int pos = vt[i][j];
            int u = findpar(pos);
            if(pos != n-1){
                int v = findpar(pos+1);
                if(v != n && u != v) par[v] = u, cur--;
            }
            if(pos != 0){
                int v = findpar(pos-1);
                if(v != n && u != v) par[v] = u, cur--;
            }
        }
        if(cur > res) res = cur;
    }
    printf("%d", res);
    return 0;
}

Compilation message (stderr)

gw.cpp: In function 'int main()':
gw.cpp:32:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<vt[i].size(); j++){
                       ^
gw.cpp:35:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<vt[i].size(); j++){
                       ^
gw.cpp:20:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
                    ^
gw.cpp:22:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &h[i]);
                           ^

• Subtask 1: 0 / 6
• Subtask 2: 0 / 6
• Subtask 3: 0 / 7
• Subtask 4: 0 / 10
• Subtask 5: 0 / 11