Submission #3695910

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Source Code Expand

import std.algorithm;
import std.array;
import std.conv;
import std.math;
import std.range;
import std.stdio;
import std.string;
import std.typecons;

T read(T)() { return readln.chomp.to!T; }
T[] reads(T)() { return readln.split.to!(T[]); }
alias readint = read!int;
alias readints = reads!int;

int calc(string s) {
    int p = cast(int) s.indexOf('I');
    if (p == -1) return 0;

    int len = 1;
    int bit = 1; // I=1, O=0
    for (int i = p + 1; i < s.length; i++) {
        if (bit && s[i] == 'O') {
            bit ^= 1;
            len++;
        }
        else if (!bit && s[i] == 'I') {
            bit ^= 1;
            len++;
        }
    }

    // O が終端なら、ひとつポップして I を終端にする
    if (!bit) len--;
    return len;
}

void main() {
    auto s = read!string;
    writeln(calc(s));
}

Submission Info

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