【Codeforces Round #351 Div. 2】 673C Bear and Colors

Bear Limak has n colored balls, arranged in one long row. Balls are numbered 1 through n, from left to right. There are n possible colors, also numbered 1 through n. The i-th ball has color ti.

For a fixed interval (set of consecutive elements) of balls we can define a dominant color. It’s a color occurring the biggest number of times in the interval. In case of a tie between some colors, the one with the smallest number (index) is chosen as dominant.

There are non-empty intervals in total. For each color, your task is to count the number of intervals in which this color is dominant.

【题目分析】

很显然有接近n^2个区间，直接暴力就是n^3的复杂度会爆炸，不妨固定一个左端点l然后r扫描过去，这样就可以做到n^2的复杂度了。

【代码】

#include <cstdio>
#include <cstring>
#include <iostream>
using namespace std;
int n,col[5010],time[5010],tong[5010],maxv,maxn;
int main()
{
scanf("%d",&n);
for (int i=1;i<=n;++i) scanf("%d",&col[i]);
for (int i=1;i<=n;++i){
memset(tong,0,sizeof tong);
maxv=0;maxn=99999;
for (int j=i;j<=n;++j){
tong[col[j]]++;
if (tong[col[j]]>maxv){
maxv=tong[col[j]];
maxn=col[j];
}
else if(tong[col[j]]==maxv&&maxn>col[j])
{
maxv=tong[col[j]];
maxn=col[j];
}
time[maxn]++;
}
}
for (int i=1;i<n;++i)
printf("%d ",time[i]);
printf("%d\n",time
);
return 0;
}