/*
Solution for APIO 2016 - Boat
Tags :
*/
#include <bits/stdc++.h>
using namespace std;
#pragma GCC target ("avx2")
#pragma GCC optimization ("Ofast")
#pragma GCC optimization ("unroll-loops")
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
typedef pair<ll, ll> pll;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define ms memset
#define pb push_back
#define fi first
#define se second
ll MOD = 1000000007;
ll power(ll base, ll n){
if (n == 0) return 1;
if (n == 1) return base;
ll halfn = power(base, n/2);
if (n % 2 == 0) return (halfn * halfn) % MOD;
return (((halfn * halfn) % MOD) * base) % MOD;
}
ll inverse(ll n){
return power(n, MOD-2);
}
ll add(ll a, ll b){
return (a+b) % MOD;
}
ll mul(ll a, ll b){
a %= MOD;
return (a*b) % MOD;
}
ll gcd(ll a, ll b){
if (a == 1) return 1;
if (a == 0) return b;
return gcd(b%a, a);
}
void solve(){
int n; cin >> n;
vector<ll> a(n), b(n); FOR(i,0,n) cin >> a[i] >> b[i];
vector<ll> dp[n];
vector<ll> pre[n];
map<ll, ll> mp;
ll ans = 0;
FOR(i,0,n){
dp[i].pb(1);
FOR(j,0,i){
dp[i][0] += pre[j][min(b[j]-a[j], a[i]-a[j])];
dp[i][0] %= MOD;
}
FOR(j,a[i], b[i]){
ll val = (dp[i][j-a[i]] + mp[j]) % MOD;
dp[i].pb(val);
}
pre[i].pb(0);
FOR(j,a[i],b[i]+1){
ll val = (pre[i][j-a[i]] + dp[i][j-a[i]]) % MOD;
pre[i].pb(val);
ll val2 = (mp[j] + dp[i][j-a[i]]) % MOD;
mp[j] = val2;
}
ans = (ans + pre[i][b[i]-a[i]+1]) % MOD;
}
cout << ans;
}
int main() {
ios::sync_with_stdio(false);
if (fopen("input.txt", "r")) {
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
}
int TC = 1;
//cin >> TC;
FOR(i, 1, TC+1){
//cout << "Case #" << i << ": ";
solve();
}
}
Compilation message
boat.cpp:10: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
10 | #pragma GCC optimization ("Ofast")
|
boat.cpp:11: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
11 | #pragma GCC optimization ("unroll-loops")
|
boat.cpp: In function 'int main()':
boat.cpp:87:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
87 | freopen("input.txt", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
boat.cpp:88:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
88 | freopen("output.txt", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Execution timed out |
2106 ms |
522316 KB |
Time limit exceeded |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
1 ms |
468 KB |
Execution killed with signal 11 |
2 |
Halted |
0 ms |
0 KB |
- |