分解因子就是logn了嘛
#include <cstdio>
#define LL long long
LL a[100010];
int n,T;
LL dp[100010][41],ans;
int r[100010][41],cnt[100010];
LL read_int () {
char c = getchar();
LL re = 0;
for(;c > '9' || c < '0'; c = getchar());
for(;c >= '0' && c <= '9'; c = getchar())
re = re * 10 + c - '0';
return re;
}
LL gcd (LL a,LL b) {
if(a % b)
return gcd(b,a % b);
return b;
}
int main () {
T = read_int();
while(T--) {
n = read_int();
for(int i = 1;i <= n;++i)
a[i] = read_int();
for(int i = 1;i <= n;++i) {
dp[i][1] = a[i];
cnt[i] = 1;
r[i][1] = i;
if(a[i] > ans)
ans = a[i];
}
for(int i = n - 1;i >= 1;--i) {
for(int j = 1;j <= cnt[i + 1];++j) {
LL t;
if(dp[i][cnt[i]] > dp[i + 1][j])
t = gcd(dp[i][cnt[i]],dp[i + 1][j]);
else t = gcd(dp[i + 1][j],dp[i][cnt[i]]);
if(t == dp[i][cnt[i]]) {
r[i][cnt[i]] = r[i + 1][j];
}
else {
dp[i][++cnt[i]] = t;
r[i][cnt[i]] = r[i + 1][j];
}
if((LL)(r[i][cnt[i]] - i + 1) * dp[i][cnt[i]] > ans)
ans = (LL)(r[i][cnt[i]] - i + 1) * dp[i][cnt[i]];
}
}
printf("%I64d\n",ans);
ans = 0;
}
}