Codeforces Round 71

第一题：读题+基础贪心

http://codeforces.com/contest/1207

第二题：思维题

题意：对于

第三题：

大佬们的dp写法：

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn = 2e5+5;
const int inf = 0x3f3f3f3f;
ll T, n, a, b, dp[maxn][2];
char s[maxn];
int main()
{
    cin >> T;
    while(T--) {
        memset(dp, inf, sizeof(dp));
        cin >> n >> a >> b;
        scanf("%s", s+1);
        dp[0][0] = b;
        for (int i = 1; i <= n; i++) 
        {
            if (s[i] == '0') 
            {
                dp[i][0] = min(dp[i][0], dp[i-1][0]+a+b);
                dp[i][0] = min(dp[i][0], dp[i-1][1]+2*a+2*b);
                dp[i][1] = min(dp[i][1], dp[i-1][0]+2*a+b);
            }
            dp[i][1] = min(dp[i][1], dp[i-1][1]+a+2*b);
        }
        cout << dp[n][0] << endl;
    }
     return 0;
}