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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#473982 | #2568. Mountains | czc | WA | 0ms | 3920kb | C++23 | 1.0kb | 2024-07-12 15:22:28 | 2024-07-12 15:22:29 |
Judging History
answer
#include<bits/stdc++.h>
using namespace std;
const int maxn=105;
int n,m,k;
const int mod=1e9+7;
#define ll long long
int a[maxn][maxn];
int c[maxn<<2][maxn<<2];
inline int h(int x,int y,int x2,int y2){
if(x-x2<0 || y2-y<0) return 0;
return c[x-x2+y2-y][x-x2];
}
int main(){
scanf("%d%d%d",&n,&m,&k);
c[0][0]=c[1][0]=c[1][1]=1;
for(int i=2;i<=max(n,m)*4;i++){
c[i][0]=1;
for(int j=1;j<=i;j++)
c[i][j]=(c[i-1][j-1]+c[i-1][j])%mod;
}
for(int i=1;i<=k;i++){
for(int j=1;j<=k;j++){
a[i][j]=h(n+i-1,i-1,j-1,m+j-1);
}
}
int f=1;
for(int i=1;i<=k;i++){
for(int j=i;j<=k;j++){
if(a[j][i]){
swap(a[j],a[i]);
if(i!=j) f*=-1;
}
}
if(!a[i][i]){
puts("0");
return 0;
}
for(int j=i+1;j<=k;j++){
while(1){
int delta=a[j][i]/a[i][i];
for(int l=1;l<=k;l++) a[j][l]=(a[j][l]-(ll)delta*a[i][l]%mod+mod)%mod;
if(!a[j][i]) break;
swap(a[j],a[i]);
f*=-1;
}
}
}
for(int i=1;i<=k;i++) f=(ll)f*a[i][i]%mod;
printf("%d",f);
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 3716kb
input:
1 1 1
output:
2
result:
ok 1 number(s): "2"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3920kb
input:
2 2 2
output:
20
result:
ok 1 number(s): "20"
Test #3:
score: 0
Accepted
time: 0ms
memory: 3728kb
input:
2 3 4
output:
490
result:
ok 1 number(s): "490"
Test #4:
score: -100
Wrong Answer
time: 0ms
memory: 3792kb
input:
1 2 8
output:
-999999962
result:
wrong answer 1st numbers differ - expected: '45', found: '-999999962'