Submission #122742

#	Time	Username	Problem	Language	Result	Execution time	Memory
122742		sealnot123	Two Antennas (JOI19_antennas)	C++14	100 / 100	713 ms	49660 KiB

antennas

#include<bits/stdc++.h>
#define x first
#define y second
#define pb push_back
#define eb emplace_back
#define all(a) (a).begin(),(a).end()
#define SZ(a) (int)(a).size()
using namespace std;
typedef long long LL;
typedef pair<LL,LL> PLL;
typedef pair<int,int> PII;
typedef double D;
typedef long double LD;
const int N = 200007;
const int INF = 1<<30;
int validMA[4*N], validMI[4*N];
int ANS[4*N], H[N], A[N], B[N];
int MA[4*N], MI[4*N], ans[N];
int n;
vector<int> come[N], go[N];
vector<PII> qq[N];

void push(int now, int l, int r){
    ANS[now] = max(ANS[now], max(validMA[now] - MI[now], MA[now] - validMI[now]));
    if(l!=r){
        if(validMA[now<<1] != -INF){
            MA[now<<1] = max(MA[now<<1], MA[now]);
            MI[now<<1] = min(MI[now<<1], MI[now]);
        }
        if(validMA[now<<1|1] != -INF){
            MA[now<<1|1] = max(MA[now<<1|1], MA[now]);
            MI[now<<1|1] = min(MI[now<<1|1], MI[now]);
        }
    }
    MA[now] = -INF;
    MI[now] = INF;
}

void add_valid(int idx, int val, int l = 1, int r = n, int now = 1){
    push(now, l, r);
    if(l == r){
        if(val==-1) validMA[now] = -INF, validMI[now] = INF;
        else validMA[now] = validMI[now] = val;
        return ;
    }
    int m = (l+r)>>1;
    if(idx <= m) add_valid(idx, val, l, m, now<<1);
    else add_valid(idx, val, m+1, r, now<<1|1);
    validMA[now] = max(validMA[now<<1], validMA[now<<1|1]);
    validMI[now] = min(validMI[now<<1], validMI[now<<1|1]);
}

void add_val(int ll, int rr, int val, int l = 1, int r = n, int now = 1){
    push(now, l, r);
    if(l > rr || r < ll || validMA[now] == -INF) return ;
    if(l >= ll && r <= rr){
        MA[now] = max(MA[now], val);
        MI[now] = min(MI[now], val);
        push(now, l, r);
        return;
    }
    int m = (l+r)>>1;
    add_val(ll, rr, val, l, m, now<<1);
    add_val(ll, rr, val, m+1, r, now<<1|1);
    ANS[now] = max(ANS[now<<1], ANS[now<<1|1]);
}

int get(int ll, int rr, int l = 1, int r = n, int now = 1){
    push(now, l, r);
    if(l > rr || r < ll) return -INF;
    if(l >= ll && r <= rr) return ANS[now];
    int m = (l+r)>>1;
    return max(get(ll, rr, l, m, now<<1), get(ll, rr, m+1, r, now<<1|1));
}

int main(){
    int i,j,k,l,a,b,c,d,q;
    scanf("%d",&n);
    for(i=1;i<=n;i++){
        scanf("%d%d%d",&H[i],&A[i],&B[i]);
        if(i+A[i]<=n) come[i+A[i]].pb(i);
        if(i+B[i]<=n) go[i+B[i]].pb(i);
    }
    scanf("%d",&q);
    for(i=1;i<=q;i++){
        scanf("%d%d",&a,&b);
        qq[b].pb({a,i});
    }
    for(i=1;i<=4*n;i++) validMA[i] = MA[i] = -INF, validMI[i] = MI[i] = INF, ANS[i] = -1;
    for(i=1;i<=n;i++){
        for(int it : come[i]) add_valid(it, H[it]);
        add_val(i-B[i], i-A[i], H[i]);
        for(PII it : qq[i]){
            ans[it.y] = get(it.x, i);
        }
        for(int it : go[i]) add_valid(it, -1);
    }
    for(i=1;i<=q;i++) printf("%d\n",ans[i]);
    return 0;
}
/*
5
10 2 4
1 1 1
2 1 3
1 1 1
100 1 1
5
1 2
2 3
1 3
1 4
1 5

20
260055884 2 15
737689751 5 5
575359903 1 15
341907415 14 14
162026576 9 19
55126745 10 19
95712405 11 14
416027186 8 13
370819848 11 14
629309664 4 13
822713895 5 15
390716905 13 17
577166133 8 19
195931195 10 17
377030463 14 17
968486685 11 19
963040581 4 10
566835557 1 12
586336111 6 16
385865831 8 9
1
1 20
*/

Compilation message (stderr)

antennas.cpp: In function 'int main()':
antennas.cpp:77:11: warning: unused variable 'j' [-Wunused-variable]
     int i,j,k,l,a,b,c,d,q;
           ^
antennas.cpp:77:13: warning: unused variable 'k' [-Wunused-variable]
     int i,j,k,l,a,b,c,d,q;
             ^
antennas.cpp:77:15: warning: unused variable 'l' [-Wunused-variable]
     int i,j,k,l,a,b,c,d,q;
               ^
antennas.cpp:77:21: warning: unused variable 'c' [-Wunused-variable]
     int i,j,k,l,a,b,c,d,q;
                     ^
antennas.cpp:77:23: warning: unused variable 'd' [-Wunused-variable]
     int i,j,k,l,a,b,c,d,q;
                       ^
antennas.cpp:78:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&n);
     ~~~~~^~~~~~~~~
antennas.cpp:80:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d",&H[i],&A[i],&B[i]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
antennas.cpp:84:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d",&q);
     ~~~~~^~~~~~~~~
antennas.cpp:86:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d",&a,&b);
         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 2 / 2
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 65 / 65