This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 200;
const int MAX_M = 5e5;
const int SIGMA = 26;
const int MOD = 1e9 + 7;
int l[MAX_M], r[MAX_M], t[MAX_M], maxR1[MAX_N + 1], maxR2[MAX_N + 1];
long long dp[MAX_N + 1][SIGMA], sp[MAX_N + 1][SIGMA];
int main() {
int n, m;
cin >> n >> m;
for ( int i = 0; i < m; i++ ) {
cin >> l[i] >> r[i];
if ( l[i] > r[i] ) {
swap( l[i], r[i] );
t[i] = 2;
maxR2[l[i]] = max( maxR2[l[i]], r[i] );
} else {
t[i] = 1;
maxR1[l[i]] = max( maxR1[l[i]], r[i] );
}
}
for ( int l = 0; l < SIGMA; l++ )
dp[1][l] = 1;
for ( int i = 1; i <= n; i++ ) {
int r1 = maxR1[i - 1], p1 = i - 1;
while ( r1 < i && p1 > 0 ) {
p1--;
r1 = max( r1, maxR1[p1] );
}
int r2 = maxR2[i - 1], p2 = i - 1;
while ( r2 < i && p2 > 0 ) {
p2--;
r2 = max( r2, maxR2[p2] );
}
for ( int l = 0; l < SIGMA; l++ ) {
for ( int m = 0; m < SIGMA; m++ ) {
if ( m == l )
continue;
dp[i][l] = (dp[i][l] + sp[i - 1][m] - sp[max( p1, p2 )][m] + MOD) % MOD;
}
}
if ( p1 > p2 ) {
for ( int l = 0; l < SIGMA; l++ ) {
for ( int m = l + 1; m < SIGMA; m++ )
dp[i][l] = (dp[i][l] + sp[p1][m] - sp[p2][m] + MOD) % MOD;
}
} else {
for ( int l = 0; l < SIGMA; l++ ) {
for ( int m = 0; m < l; m++ )
dp[i][l] = (dp[i][l] + sp[p2][m] - sp[p1][m] + MOD) % MOD;
}
}
for ( int l = 0; l < SIGMA; l++ )
sp[i][l] = (sp[i - 1][l] + dp[i][l]) % MOD;
}
/*for ( int i = 0; i <= n; i++ ) {
for ( int l = 0; l < SIGMA; l++ )
printf( "%d ", dp[i][l] );
printf( "\n" );
}*/
int ans = 0;
for ( int i = 1; i <= n; i++ ) {
for ( int l = 0; l < SIGMA; l++ )
ans = (ans + dp[i][l]) % MOD;
}
cout << ans;
return 0;
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |