# UUID: 71b8761b-e1db-448f-9a74-45da67cdd91f
from sys import stdin, setrecursionlimit
input = stdin.readline
setrecursionlimit(10**6)
N = int(input())
negy=[]
ot=[]
for i in range(1,N+1):
S, M = map(int,input().split())
if M==4:
negy.append((S,i))
elif M>4:
ot.append((S,i))
negy.sort()
ot.sort()
def test(k):
ans = []
i = len(negy)-1
j = len(ot)-1
for day in range(k,0,-1):
if 0 <= i and negy[i][0] >= day:
if 0 <= j and ot[j][0] >= day:
ans.append((negy[i][1],ot[j][1]))
i -= 1
j -= 1
else:
return False, []
elif 1 <= j and ot[j-1][0] >= day:
ans.append((ot[j][1],ot[j-1][1]))
j -= 2
else:
return False, []
return True, ans
lo = 0
hi = 2001
res = []
while hi-lo > 1:
mid = (hi+lo)//2
ok, ans = test(mid)
if ok:
lo = mid
res = ans
else:
hi = mid
print(lo)
res.reverse()
for line in res:
print(*line)| Subtask | Sum | Test | Verdict | Time | Memory | ||
|---|---|---|---|---|---|---|---|
| subtask1 | 0/0 | ||||||
| 1 | Accepted | 43ms | 19688 KiB | ||||
| subtask2 | 10/10 | ||||||
| 2 | Accepted | 39ms | 19888 KiB | ||||
| 3 | Accepted | 43ms | 19636 KiB | ||||
| 4 | Accepted | 43ms | 19636 KiB | ||||
| 5 | Accepted | 39ms | 19896 KiB | ||||
| 6 | Accepted | 45ms | 19736 KiB | ||||
| 7 | Accepted | 39ms | 19688 KiB | ||||
| 8 | Accepted | 43ms | 19620 KiB | ||||
| 9 | Accepted | 39ms | 19708 KiB | ||||
| 10 | Accepted | 45ms | 19692 KiB | ||||
| 11 | Accepted | 39ms | 19528 KiB | ||||
| subtask3 | 20/20 | ||||||
| 12 | Accepted | 39ms | 19660 KiB | ||||
| 13 | Accepted | 45ms | 19620 KiB | ||||
| 14 | Accepted | 43ms | 19688 KiB | ||||
| 15 | Accepted | 43ms | 19576 KiB | ||||
| 16 | Accepted | 39ms | 19584 KiB | ||||
| 17 | Accepted | 43ms | 21216 KiB | ||||
| 18 | Accepted | 50ms | 21216 KiB | ||||
| 19 | Accepted | 43ms | 20012 KiB | ||||
| 20 | Accepted | 50ms | 21072 KiB | ||||
| 21 | Accepted | 57ms | 21536 KiB | ||||
| 22 | Accepted | 43ms | 21212 KiB | ||||
| 23 | Accepted | 57ms | 21712 KiB | ||||
| 24 | Accepted | 57ms | 21708 KiB | ||||
| 25 | Accepted | 59ms | 21460 KiB | ||||
| 26 | Accepted | 48ms | 21120 KiB | ||||
| 27 | Accepted | 59ms | 21740 KiB | ||||
| 28 | Accepted | 71ms | 21652 KiB | ||||
| 29 | Accepted | 52ms | 21228 KiB | ||||
| 30 | Accepted | 54ms | 21600 KiB | ||||
| 31 | Accepted | 59ms | 21780 KiB | ||||
| subtask4 | 15/15 | ||||||
| 32 | Accepted | 43ms | 19568 KiB | ||||
| 33 | Accepted | 43ms | 19740 KiB | ||||
| 34 | Accepted | 39ms | 19564 KiB | ||||
| 35 | Accepted | 45ms | 21148 KiB | ||||
| 36 | Accepted | 59ms | 21468 KiB | ||||
| 37 | Accepted | 52ms | 21428 KiB | ||||
| 38 | Accepted | 48ms | 21196 KiB | ||||
| 39 | Accepted | 39ms | 19912 KiB | ||||
| 40 | Accepted | 45ms | 21212 KiB | ||||
| 41 | Accepted | 54ms | 21752 KiB | ||||
| 42 | Accepted | 59ms | 21420 KiB | ||||
| 43 | Accepted | 68ms | 21920 KiB | ||||
| 44 | Accepted | 46ms | 19936 KiB | ||||
| 45 | Accepted | 52ms | 21548 KiB | ||||
| 46 | Accepted | 64ms | 21952 KiB | ||||
| subtask5 | 15/15 | ||||||
| 47 | Accepted | 48ms | 21116 KiB | ||||
| 48 | Accepted | 45ms | 21216 KiB | ||||
| 49 | Accepted | 50ms | 21112 KiB | ||||
| 50 | Accepted | 43ms | 21044 KiB | ||||
| 51 | Accepted | 46ms | 21216 KiB | ||||
| 52 | Accepted | 48ms | 21216 KiB | ||||
| 53 | Accepted | 48ms | 21216 KiB | ||||
| 54 | Accepted | 46ms | 21168 KiB | ||||
| 55 | Accepted | 45ms | 19684 KiB | ||||
| 56 | Accepted | 52ms | 21512 KiB | ||||
| 57 | Accepted | 43ms | 21108 KiB | ||||
| 58 | Accepted | 46ms | 21044 KiB | ||||
| 59 | Accepted | 50ms | 21484 KiB | ||||
| 60 | Accepted | 48ms | 21220 KiB | ||||
| 61 | Accepted | 45ms | 19936 KiB | ||||
| subtask6 | 15/15 | ||||||
| 62 | Accepted | 45ms | 21416 KiB | ||||
| 63 | Accepted | 56ms | 21188 KiB | ||||
| 64 | Accepted | 57ms | 21720 KiB | ||||
| 65 | Accepted | 71ms | 21856 KiB | ||||
| 66 | Accepted | 76ms | 22328 KiB | ||||
| 67 | Accepted | 43ms | 21216 KiB | ||||
| 68 | Accepted | 50ms | 21416 KiB | ||||
| 69 | Accepted | 50ms | 21272 KiB | ||||
| 70 | Accepted | 54ms | 21220 KiB | ||||
| 71 | Accepted | 68ms | 21720 KiB | ||||
| 72 | Accepted | 50ms | 21476 KiB | ||||
| 73 | Accepted | 54ms | 21424 KiB | ||||
| 74 | Accepted | 63ms | 21644 KiB | ||||
| 75 | Accepted | 59ms | 21460 KiB | ||||
| 76 | Accepted | 43ms | 21216 KiB | ||||