QOJ.ac
QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#630801 | #7780. Dark LaTeX vs. Light LaTeX | Akoasm_X | AC ✓ | 1052ms | 102056kb | C++20 | 4.5kb | 2024-10-11 20:28:48 | 2024-10-11 20:28:49 |
Judging History
你现在查看的是测评时间为 2024-10-11 20:28:49 的历史记录
- [2024-11-25 20:53:52]
- hack成功,自动添加数据
- (/hack/1258)
- [2024-10-11 20:28:48]
- 提交
answer
#include<bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define mp make_pair
#define pb push_back
typedef long long LL;
inline int read(){
int x = 0 , f = 1 ; char c = getchar() ;
while( c < '0' || c > '9' ) { if( c == '-' ) f = -1 ; c = getchar() ; }
while( c >= '0' && c <= '9' ) { x = x * 10 + c - '0' ; c = getchar() ; }
return x * f ;
}
const int maxn = 5020;
LL Ans;
int n,m,cnt;
int z[maxn],s[maxn][maxn],S[maxn],v[maxn];
int nxt[maxn];
char A[maxn],B[maxn];
void Clear(){
for(int i=0;i<=n;i++)
for(int j=0;j<=n;j++)
s[i][j] = 0;
cnt = 0;
}
void getlcp(char ss[],int id){
int N = strlen(ss);
for(int i=0;i<=n;i++) z[i] = 0;
for (int i = 1, l = 0, r = 0; i < N; ++i) {
if (i <= r && z[i - l + id] < r - i + 1) {
z[i + id] = z[i - l + id];
}
else {
z[i + id] = max(0, r - i + 1);
while (i + z[i + id] < n && ss[z[i + id]] == ss[i + z[i + id]]) ++z[i + id];
}
if (i + z[i + id] - 1 > r) l = i, r = i + z[i + id] - 1;
}
int i = id;
for(int j=i+2;j<=n;j++){
int t = z[j];
t = min(t,j - 1 - i);
s[i+1][j-1]++;
s[i+t+1][j-1]--;
}
}
void bf(char ss[],int id){
int N = strlen(ss+1);
int pos = 0;
for(int i=1;i<=n;i++) nxt[i] = v[i] = 0;
for(int i=2;i<=N;i++){
while(pos&&ss[pos+1]!=ss[i]) pos=nxt[pos];
if(ss[pos+1]==ss[i]) pos++;
nxt[i] = pos;
}
pos = 0;
for(int i=0;i<=n;i++) S[i] = 0;
for(int i=1;i<=m;i++){
while(pos&&ss[pos+1]!=B[i]){
pos = nxt[pos];
// if(id==9) cout<<i<<endl;
// S[id]++;
// S[id+pos]--;
//v[pos]++;
}
if(ss[pos+1]==B[i]) pos++;
// if(pos==1&&id==9) cout<<i<<endl;
// if(id==9) cout<<pos<<" "<<i<<endl;
// S[id+pos-1]++;
// S[id+pos]--;
v[pos]++;
}
// while(pos){
// S[id]++;
// S[id+pos]--;
// pos = nxt[pos];
// }
for(int i=n;i>=1;i--){
v[nxt[i]] += v[i];
// if(v[i]) cout<<"ttt"<<" "<<id<<" "<<i<<" "<<v[i]<<endl;
// S[id]+=v[i];
// S[id+i]-=v[i];
}
for(int i=1;i<=n;i++) S[i] += S[i-1];
for(int i=id;i<=n;i++){
// if(v[i-id+1]&&s[id][i]) cout<<id<<" "<<i<<" "<<v[i-id+1]<<" "<<s[id][i]<<endl;
Ans += v[i-id+1] * s[id][i];
}
}
void BF(char *ss,int id){
int N = strlen(ss+1);
int pos = 0;
for(int i=1;i<=N;i++) nxt[i] = 0;
for(int i=2;i<=N;i++){
while(pos&&ss[pos+1]!=ss[i]) pos=nxt[pos];
if(ss[pos+1]==ss[i]) pos++;
nxt[i] = pos;
}
pos = 0;
for(int i=0;i<=n;i++) S[i] = v[i] = 0;
for(int i=1;i<=m;i++){
while(pos&&ss[pos+1]!=B[i]){
pos = nxt[pos];
// if(id==9) cout<<i<<endl;
// S[id]++;
// S[id+pos]--;
//v[pos]++;
}
if(ss[pos+1]==B[i]) pos++;
// if(pos==1&&id==9) cout<<i<<endl;
// if(id==9) cout<<pos<<" "<<i<<endl;
// S[id+pos-1]++;
// S[id+pos]--;
v[pos]++;
}
// while(pos){
// S[id]++;
// S[id+pos]--;
// pos = nxt[pos];
// }
for(int i=n;i>=1;i--){
v[nxt[i]] += v[i];
// if(v[i]) cout<<"ttt"<<" "<<id<<" "<<i<<" "<<v[i]<<endl;
// S[id]+=v[i];
// S[id+i]-=v[i];
}
for(int i=1;i<=n;i++) S[i] += S[i-1];
for(int i=id;i<=n;i++){
// if(v[i-id+1]&&s[id][i]) cout<<id<<" "<<i<<" "<<v[i-id+1]<<" "<<s[id][i]<<endl;
Ans += v[i-id+1];// * s[id][i];
}
}
void solve(){
scanf("%s",A+1);n = strlen(A+1);
scanf("%s",B+1);m = strlen(B+1);
for(int i=1;i<=n;i++) getlcp(A+i,i);
for(int j=1;j<=n;j++){
for(int i=1;i<=n;i++){
s[i][j] += s[i-1][j];
}
}
for(int i=1;i<=n;i++) bf(A+i-1,i);
// cout<<Ans<<endl;
Clear();
swap(A,B);
swap(n,m);
// build();
for(int i=1;i<=n;i++) getlcp(A+i,i);
for(int j=1;j<=n;j++){
for(int i=1;i<=n;i++){
s[i][j] += s[i-1][j];
}
}
for(int i=1;i<=n;i++) bf(A+i-1,i);
// cout<<Ans<<endl;
for(int i=1;i<=n;i++) BF(A+i-1,i);
printf("%lld\n",Ans);
}
int main(){
// freopen("1.txt","r",stdin);
int T = 1;
// T = read();
while(T--) solve();
return 0;
}
这程序好像有点Bug,我给组数据试试?
详细
Test #1:
score: 100
Accepted
time: 0ms
memory: 3908kb
input:
abab ab
output:
8
result:
ok 1 number(s): "8"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3932kb
input:
abab abaaab
output:
29
result:
ok 1 number(s): "29"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3936kb
input:
abcd abcde
output:
10
result:
ok 1 number(s): "10"
Test #4:
score: 0
Accepted
time: 0ms
memory: 3936kb
input:
aaba ba
output:
6
result:
ok 1 number(s): "6"
Test #5:
score: 0
Accepted
time: 0ms
memory: 6092kb
input:
babababaaabbaabababbbaabbbababbaaaaa aaaabbaababbab
output:
1161
result:
ok 1 number(s): "1161"
Test #6:
score: 0
Accepted
time: 605ms
memory: 102056kb
input:
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa...
output:
78156256250000
result:
ok 1 number(s): "78156256250000"
Test #7:
score: 0
Accepted
time: 12ms
memory: 23108kb
input:
gzgzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggzggzgzggzggzgzggzgzggz...
output:
60716448
result:
ok 1 number(s): "60716448"
Test #8:
score: 0
Accepted
time: 16ms
memory: 22820kb
input:
mlmllmllmlmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmlmllmllmlmllmllmlmllmlmllmllmlmllmlmllml...
output:
60679828
result:
ok 1 number(s): "60679828"
Test #9:
score: 0
Accepted
time: 428ms
memory: 101992kb
input:
vbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvbbvbvbbvbbvbvbbvbvbbvb...
output:
2655796915
result:
ok 1 number(s): "2655796915"
Test #10:
score: 0
Accepted
time: 435ms
memory: 101932kb
input:
ttdtdttdttdtdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdtdttdttdtdttdttdtdttdtdttdttdtdttdttdt...
output:
2652657341
result:
ok 1 number(s): "2652657341"
Test #11:
score: 0
Accepted
time: 406ms
memory: 101984kb
input:
uupuupupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupupuupuupupuupuupupuupupuupuupupuupuupupuupu...
output:
2619083676
result:
ok 1 number(s): "2619083676"
Test #12:
score: 0
Accepted
time: 20ms
memory: 22964kb
input:
ggxgxggxggxgxggxggxgxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxgxggxgxggxggxgxggxggxgxggxgxggxggxg...
output:
61227979
result:
ok 1 number(s): "61227979"
Test #13:
score: 0
Accepted
time: 150ms
memory: 64428kb
input:
cwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwcwwcwwcwcwwcwwcwcw...
output:
834307544
result:
ok 1 number(s): "834307544"
Test #14:
score: 0
Accepted
time: 411ms
memory: 102044kb
input:
trtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtrttrttrtrttrtrttrttrtr...
output:
2663862697
result:
ok 1 number(s): "2663862697"
Test #15:
score: 0
Accepted
time: 19ms
memory: 24876kb
input:
gggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggggg...
output:
0
result:
ok 1 number(s): "0"
Test #16:
score: 0
Accepted
time: 696ms
memory: 101916kb
input:
igkkcgocckgoocioiiggcgkigoggkociciigokikkcogkoookkiioikockoigokigiiciikcokoockgiiiogicgkkgoiogcggcgckgikccgcckoocgggogiccgkgcoccckgiooiogckoioiioogiicogkckgiickooiockogkoikogkkociioigocoiioccggkigciigcckkggiccciiiggkcgggcokookogiokoccccgogkcigokkckccoccgkoogokogkcioockkikigokiikkkoikiigckkooioogioio...
output:
1707132
result:
ok 1 number(s): "1707132"
Test #17:
score: 0
Accepted
time: 39ms
memory: 22832kb
input:
jkkkjjjkjkkkjjjjkkkkkjjjjjjkjjjjkjjjkkkjkjkkkkjjkkjjjkjkjjjkkkkjkjjkkkkkkkjkkkjkkjkkjjkkjjkjjjkkkjkjjkjkjjjjkkjjjjjjkkjjjkkkjkjkkkkkjkjjkjjkkkkkkkkjkkkjjkjjkkkjkjjkjjkkjjkkkkkjjjjjjkjjjkkjkjjkjjjkjkkjkjkkkkjjkkjkkjkkkjkkkkkkkjkjjkkjkjjkjkkkkkkkjkkjkkkkjkjkkkkkkkjkkjjkjjjkjjkkkkjkjkkjjjjjkjkjjjjkjkkk...
output:
2954810
result:
ok 1 number(s): "2954810"
Test #18:
score: 0
Accepted
time: 21ms
memory: 24844kb
input:
juxqlncuflculraueufcupffalouceftcepluhuupphohougacfftcrouohhnxopoguocjlpqpgppuhllpsnllqnftprunnucfcucclcplxuatfxtnljnuxnhapanlrpuexuflusncrapcrqpoganppxlloougftptxutfcrgchspahqghstuuefntfuauohlxlenpujeupuucnljxuunanustpuppllelnjcupqppaorpexophphnaopsxajtonupocuuoffpuqagutpuntfloalhrffhlrltghulpuoqop...
output:
40401
result:
ok 1 number(s): "40401"
Test #19:
score: 0
Accepted
time: 566ms
memory: 102040kb
input:
lmvbtqzhgzztvlsvzdesvgefvzkqfbvszmqjsgthnmhtifhztvhihdvgeqmhvzzqmqjhdmmteshvjbgvsfzgkivmvggvzbvzlemnmqhvqfmkmvmqhfqeehqvkgsedzmgbheeielzqzqtfzzvvjfievbzhdkfivhksmzbegkzsilnzgnzbqeqtghdzljvvfedmkeivmnzznhfhekvzeqvvfvqzehdhvsmklbzhhfzdtzqlmhehqqvkbqmvlzvmlzmzdzdbvmmmzimmqvleggmzigqmivqzqhvkezgmjvvivvg...
output:
1421341
result:
ok 1 number(s): "1421341"
Test #20:
score: 0
Accepted
time: 39ms
memory: 22984kb
input:
cccfcccffcffffffcfffffccffffffcccffffcffccfcffcfcfffcfcffcfcfcccccccfcffcfccccccffcccfcccfcccccccffcffffffcfccffcccfcfccfcffcfffccffccfffffccfcffcffffffffccfffffffccffcfccfcfcfffccfffffccccfcfccfccfcfcfccccfcccffccccfcccfccccfcfcffcccffcfffcfcccccffccfcccccccfffcffcccccccccccccfcfcffcffcffcffcffcfcf...
output:
3118221
result:
ok 1 number(s): "3118221"
Test #21:
score: 0
Accepted
time: 1052ms
memory: 101984kb
input:
srrsrssrrsssrsrsrsrrrrrssrrssrsrsssrrrrsssrrsrrrsrrrrssrsssrssrrrsrrsrsssssrrrrrrrrrrsrrssrsrrrrrsssrrrrsssrsrrsrsssrrrrrsrrssrrssrrrrsrrsrsrsrrrsrrrrssrrssssrsrrrrsrssrsrsssssssrsrrsrrrrrsrssssrrsssrsssrrrrsssssrsrrrsssrssrrrssrsrsssssrrrssrrrrrsssrrsrrsrrrssrrssrsrsrssssrssssrsrrrsrrssrsrsrsrsrsrr...
output:
75529025
result:
ok 1 number(s): "75529025"
Test #22:
score: 0
Accepted
time: 614ms
memory: 101916kb
input:
onpboooppuaeabbabzpoopnqpopnyrabrrpbyorlebzprboypaprrpabebdobozuborppyualtbzauprrobnrqbzuzrrbebotqulratlrobaoyztyrpqqroorbyledaropnnploroabtelydozdopabapqubynynubpybptpoopnyrolparqpaoooobbperyuezponoboyuaopbpqpporplbdrooozbybueyrpnpzodrroyarzbpzyprpdpzboaaobpppalllranutyaobbdptrpprzubdbryapbudylbqab...
output:
3326939
result:
ok 1 number(s): "3326939"
Test #23:
score: 0
Accepted
time: 28ms
memory: 23100kb
input:
etweelwwwwwtttweetleettetlwwlltwwettwtwwlttletlwtltwtwelltetteleelelwwttelwleweltewtwllltwweeelwtweweeweetltttwtelteltwtewteetwwtltwetlteettelwtewtlletlltllwtweewletwtwtleewttlellwwteettlwtttwteetwwltwttelltweetttwtelleleetwewlewewewtewtetttweteeweltltelwwlwltlletwlweelelwlwelelettwllwlewleteeteellw...
output:
547040
result:
ok 1 number(s): "547040"
Test #24:
score: 0
Accepted
time: 24ms
memory: 23032kb
input:
wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww...
output:
38791844792
result:
ok 1 number(s): "38791844792"
Test #25:
score: 0
Accepted
time: 223ms
memory: 62852kb
input:
pppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppppp...
output:
4804791846049
result:
ok 1 number(s): "4804791846049"
Test #26:
score: 0
Accepted
time: 592ms
memory: 102056kb
input:
jjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjjj...
output:
10043476749324
result:
ok 1 number(s): "10043476749324"
Test #27:
score: 0
Accepted
time: 309ms
memory: 86980kb
input:
yhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyyhhyhyyhhyyh...
output:
269398620
result:
ok 1 number(s): "269398620"
Test #28:
score: 0
Accepted
time: 326ms
memory: 87240kb
input:
yhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyhyyhyhhyyhhyhyyhyhhyhyyhhyyhyhhyyhhyhyyhhyyh...
output:
269769773
result:
ok 1 number(s): "269769773"
Test #29:
score: 0
Accepted
time: 317ms
memory: 87536kb
input:
baababbaabbabaababbabaabbaababbaabbabaabbaababbabaababbaabbabaababbabaabbaababbabaababbaabbabaabbaababbaabbabaababbabaabbaababbaabbabaabbaababbabaababbaabbabaabbaababbaabbabaababbabaabbaababbabaababbaabbabaababbabaabbaababbaabbabaabbaababbabaababbaabbabaababbabaabbaababbabaababbaabbabaabbaababbaabba...
output:
287077563
result:
ok 1 number(s): "287077563"
Extra Test:
score: 0
Extra Test Passed