Code in c++ for largest rectangle in histogram Solution #include #define ll long long #define N_lim 100010 ll max(ll a, ll b) { return a>b?a:b; } ll largestArea(int h[], int n) { ll i, top = 1, area = 0, S[N_lim]; h[0] = S[0] = h[++n] = 0; for(i=1; i<=n; i++) { while(top>1 && h[S[top-1]]>=h[i]) { area = max(area, (ll)h[S[top-1]]*(ll)(i - S[top-2]-1)); top--; } S[top++] = i; } return area; } int main() { int n, i, h[N_lim]; while(scanf(\"%d\", &n)==1 && n) { for(i=1; i<=n; i++) scanf(\"%d\", &h[i]); printf(\"%lld\ \", largestArea(h, n)); } return 0; }.

1. Code in c++ for largest rectangle in histogram
Solution
#include
#define ll long long
#define N_lim 100010
ll max(ll a, ll b)
{
return a>b?a:b;
}
ll largestArea(int h[], int n)
{
ll i, top = 1, area = 0, S[N_lim];
h[0] = S[0] = h[++n] = 0;
for(i=1; i<=n; i++)
{
while(top>1 && h[S[top-1]]>=h[i])
{
area = max(area, (ll)h[S[top-1]]*(ll)(i - S[top-2]-1));
top--;
}
S[top++] = i;
}
return area;
}
int main()
{
int n, i, h[N_lim];
while(scanf("%d", &n)==1 && n)
{
for(i=1; i<=n; i++) scanf("%d", &h[i]);
printf("%lld ", largestArea(h, n));
}
return 0;

2. }