【51NOD 1478】括号序列的最长合法子段

#include<cstdio>
#include<cstring>
#include<algorithm>
using namespace std;
const int N = 1E6 + 3;
char s
;
int main() {
scanf("%s", s);
int n = strlen(s), now = 0, ans = 0, ans2, sum = 0, top = 0, tmp = 0;
for(int i = 0; i < n; ++i)
if (s[i] == '(')
++top;
else {
if (top) {
--top;
sum += 2;
} else {
if (sum > now) {
now = sum; ans = 1;
} else
if (sum == now)
++ans;
tmp = i + 1;
top = 0;
sum = 0;
}
}

if (top) {
ans2 = 0; sum = 0; top = 0;
for(int i = n - 1; i >= tmp; --i)
if (s[i] == ')')
++top;
else {
if (top) {
--top;
sum += 2;
} else {
if (sum > now) {
now = sum; ans = 1;
} else
if (sum == now)
++ans;
top = 0;
sum = 0;
}
}
if (sum > now)
now = sum, ans = 1;
else
if (sum == now)
++ans;
} else {
if (sum > now)
now = sum, ans = 1;
else
if (sum == now)
++ans;
}

if (now == 0)
ans = 1;
printf("%d %d\n", now, ans);
return 0;
}